Asked by: Djuan Cole

Why are all orbitals in hydrogen degenerate?

Degeneracy: The property of having the same energy. Two orbitals are degenerate if, and only if, they have the exact same energy. For hydrogen, the 2s and 2p orbitals are degenerate because they have the same value of n. For helium (a two-electron atom), the 2s and 2p orbitals are not degenerate.

Are all orbitals in hydrogen degenerate?

In general, the more complications you add, like more electrons, neighboring atoms, magnetic fields, etc, the fewer orbitals are degenerate. So for a hydrogen atom by itself, all the orbitals in each shell are degenerate. When you move to a lonely helium atom, the orbitals in the subshells are degenerate.

Are all orbitals in the same shell in a hydrogen atom are degenerate?

In hydrogen, all orbitals with the same principal quantum number ‘n’ (1,2,3…) are degenerate, regardless of the orbital angular momentum quantum number’l’ (0,1…n-1 or s,p,d..). However, in atoms with more than one electron, orbitals with different values of l for a given value for n are not degenerate.

Why is the hydrogen atom degenerate?

Because all orbitals with the same principal quantum number have the same energy in one-electron systems, each orbital energy level is n2-degenerate.

What makes an orbital degenerate?

Degenerate orbitals definition:



Electron orbitals having the same energy levels are called degenerate orbitals. As per the Aufbau principle, lower energy levels are filled before higher energy levels. As per Hund’s rule, degenerate orbitals are filled evenly before electrons are filled into higher energy levels.

What are degenerate orbitals explain with examples?

Degenerate Orbitals Example



Example: An atom has four orbitals, namely s, p, d, and f. The p orbital has three orbitals px, py, and pz. All these three orbitals have similar energy belonging to the same orbital (p), hence are called degenerate molecular orbitals.

What is the difference between degenerate and non degenerate orbitals?

The key difference between degenerate and non-degenerate semiconductors is that in degenerate semiconductors, the injection of electrons or holes is only possible from the Fermi energy level, whereas non-degenerate semiconductors can cause the formation of two types of contacts to organic material.

Which two of the following orbitals are degenerate?

The orbitals which belongs to same subshell and same shell are called degenerate orbitals. (3dxy,3dz2,3dyz) and (4dxy,4dyz,4dz2) are the two sets of degenerate orbitals.

What does degenerate mean in chemistry?

of equal energy

Degenerate: Systems (molecules, electrons, orbitals, resonance contributors, etc.) that are of equal energy.

What does it mean for energy levels to be degenerate?

In quantum mechanics, an energy level is degenerate if it corresponds to two or more different measurable states of a quantum system. Conversely, two or more different states of a quantum mechanical system are said to be degenerate if they give the same value of energy upon measurement.

Do all hydrogen atomic orbitals have the same energy?

In the case of a hydrogen atom or a one-electron ion (such as He⁺, Li²⁺, and so on), energies of all the orbitals with the same n are the same. This is called a degeneracy, and the energy levels for the same principal quantum number, n, are called degenerate energy levels.

Do all hydrogen orbitals have the same energy?

In the many-electron atom all orbitals with the same value of the principal quantum number n do not have the same energy as they do in the case of hydrogen. For the many-electron atoms, the energy of an orbital depends on both n and l, the energy increasing as l increases even when n is constant.

What is the degeneracy of the level of the hydrogen atom?

Thus the total number of degenerate orbitals present in the third shell are 1 + 3 + 5 = 9 degenerate orbitals. Hence the degeneracy of the given hydrogen atom is 9.

Which quantum numbers must be the same for the orbitals that they designate to be degenerate in a one electron system such as hydrogen )?

The principal quantum number and the azimuthal quantum number must be the same for the orbitals that they designate to be degenerate in a many-electron system.

How do you find degeneracy?

Note: Degeneracy of orbitals means that the orbitals are of equal energy. Such orbitals are called degenerate orbitals. In hydrogen the level of energy degeneracy is as follows: 1s, 2s = 2p, 3s = 3p = 3d, 4s = 4p = 4d = 4f,…

Are the 3s 3p and 3d orbitals in hydrogen degenerate?

As given in the above representation, 2s and 2p orbitals are degenerate; 3s, 3p and 3d orbitals are degenerate, and so on. The degeneracy of the orbitals breaks down in the case of multi-electron systems. This is because of the shielding effect by the electrons present in the orbitals of s, p, d, f and so on.

What is orbital degeneracy?

Degenerate orbitals are the orbitals of the same subshell having equal energies. When the electrons of the orbitals are not influenced by any external factors like an electric field or magnetic field, they have same energies.

Which pair of orbitals given below for H atom are degenerate?

(3) In hydrogen atom 3s, 3px and 3d orbitals are degenerate because they are all in the third shell. In hydrogen atom subshells of the same shell have equal energy, unlike other multi-electron atoms. Hope it helps you.

How many degenerate orbitals are there in the n 3 shell of the hydrogen atom?

There are nine orbitals in the n = 3 shell. There is one orbital in the 3s subshell and three orbitals in the 3p subshell.

Which orbitals are degenerate in the hydrogen atom with N 3?

Picture a n=3 atom for this problem that has no element attached to it in that case all orbitals would be equal energy therefore it would be option E because all orbitals s,p,and d would be degenerate.

Which two of the following orbitals are degenerate?

The orbitals which belongs to same subshell and same shell are called degenerate orbitals. (3dxy,3dz2,3dyz) and (4dxy,4dyz,4dz2) are the two sets of degenerate orbitals.

Asked by: Djuan Cole

Which of following has the highest chemical shift ppm value?

Solution: Generally, -COOH (acids) gives highest Chemical Shift values.

What is chemical shift and how it is measured?

The chemical shift in absolute terms is defined by the frequency of the resonance expressed with reference to a standard compound which is defined to be at 0 ppm. The scale is made more manageable by expressing it in parts per million (ppm) and is indepedent of the spectrometer frequency.

Which of the following molecules will show highest chemical shift?

Dear Ting, carboxylic acids with the structure R-COOH have the highest chemical shift: in the range 10-13 ppm.

Which of the following compounds gives the highest chemical shift value in the NMR spectrum?

Answer and Explanation: The proton labeled Hc will give the highest chemical shift.

How do you know if its a chemical shift?

Chemical shift is equal to the observed shift from TMS in hertz, times 10 to the sixth, divided by the spectrometer frequency in hertz.

Which one of the following factors does not affect the chemical shift?

A catalyst do not affect the equilibrium state of a reaction. It helps the system to reach chemical equilibrium faster.

What affects chemical shift in NMR?

The proton NMR chemical shift is affect by nearness to electronegative atoms (O, N, halogen.) and unsaturated groups (C=C,C=O, aromatic). Electronegative groups move to the down field (left; increase in ppm).

What causes higher chemical shift in NMR?

Electronegative atoms present in molecules tend to draw the electron density towards themselves and deshield the nucleus. An increase in electronegativity of the surrounding groups will result in decrease of the electron density and lead to an increase in chemical shift value due to the shielding of the nucleus.

What increases chemical shift?

Electron with-drawing groups can decrease the electron density at the nucleus, deshielding the nucleus and result in a larger chemical shift.

Which proton in hex 3 EN 2 One shows the largest most downfield chemical shift in the 1H NMR spectrum?

Answer and Explanation: In the given molecule, The carbon with the largest downfield shift (highest number) in the C13 – NMR is b) C2 where the carbonyl oxygen is attached.

What do you mean by chemical shift?

Medical Definition of chemical shift



: the characteristic displacement of the magnetic resonance frequency of a sample nucleus from that of a reference nucleus that provides the basis for generating and interpreting nuclear magnetic resonance and magnetic resonance imaging data.

What causes a downfield shift in NMR?

Because the proton experiences higher external magnetic field, it needs a higher frequency to achieve resonance, and therefore, the chemical shift shifts downfield (higher ppms) .

What are the two scales used to calculate chemical shift values?

The two most common standards are TMS (tetramethylsilane, (Si(CH₃)₄) which has been assigned a chemical shift of zero, and CDCl₃ (deuterochloroform) which has a chemical shift of 7.26 for ¹H NMR and 77 for ¹³C NMR.

What does higher ppm mean NMR?

Downfield

Downfield means higher energy – left side of the spectrum (higher ppm) Upfield means lower energy – right side of the spectrum (lower ppm)

What is chemical shift value?

In nuclear magnetic resonance (NMR) spectroscopy, the chemical shift is the resonant frequency of an atomic nucleus relative to a standard in a magnetic field. Often the position and number of chemical shifts are diagnostic of the structure of a molecule.

Which proton in hex 3 EN 2 One shows the largest most downfield chemical shift in the 1H NMR spectrum?

Answer and Explanation: In the given molecule, The carbon with the largest downfield shift (highest number) in the C13 – NMR is b) C2 where the carbonyl oxygen is attached.

What does ppm mean in NMR?

Parts Per Million

Parts Per Million in NMR Spectroscopy. The chemical shift of a hydrogen atom is really the frequency at which it is said to undergo resonance. However, when we describe the chemical shift of hydrogen atoms, we do not use Hertz (cycles per second) but rather use units called parts per million or ppm.

What causes chemical shift in NMR spectroscopy?

There are two major factors that cause different chemical shifts (a) deshielding due to reduced electron density (due electronegative atoms) and (b) anisotropy (due to π bonds). Coupling = Due to the proximity of “n” other equivalent H atoms, causes the signals to be split into (n+1) lines.

What determines chemical shift in NMR?

The proton NMR chemical shift is affect by nearness to electronegative atoms (O, N, halogen.) and unsaturated groups (C=C,C=O, aromatic). Electronegative groups move to the down field (left; increase in ppm).

Asked by: Joshua Thomaz

Does PCl5 dissociate?

PCl5 dissociates as PCl5(g) PCl3 (g) + Cl2(g) .

What is the decomposition reaction of PCl5?

Phosphorus pentachloride decompose according to the reaction PCl3(g)⇌PCl3(g)+Cl2(g), 1 mol of PCl5 is placed in a 500 mL closed reaction vessel and allowed to reach equilibrium with decomposition products, phosphorus trichloride and chlorine at 523 K.

What will be the effect on KC if more PCl5 is added?

(i) K_c remains unchanged when more PCl₅ is added. (ii) When pressure is increased, K_c remains unchanged. (iii) As given reaction is endothermic, on increasing the temperature, A_f will increase.

What is the value of Kc for the reverse reaction 1 point?

As the value of the reaction quotient is greater than the value of Kc i.e. 1×10−4 the reaction will proceed in the reverse direction.

What is the equilibrium concentration of PCl5?

In the reaction PCl5(g)⇔PCl3(g)+Cl2(g) the equilibrium concentration of PCl5 and PCl3 are 0.4 and 0.2 mole/litre respectively.

What is the percent dissociation of PCl5 at equilibrium?

PCl(5) is 10% dissociated at 1 atm.

Why does PCl5 dissociate on heating?

Pcl5 has a trigonal pyramidal shape. The bond pair – bond pair repulsion is greater in the two axial P-Cl bonds as compared to the three equatorial P-Cl bonds. So the axial P-Cl bonds are less stable and are removed readily when PCl5 is heated.

When PCl5 is heated and if dissociates?

When `PCl_(5)` is heated, it dissociates into `PCl_(3)` and `Cl_(2)`. The vapour density of the gas mixture at `200^(@)C` and at `250^(@)C` is `70` and `58`, respectively.

What is the heat of reaction PCl5?

7Kcal.

What is the relation between KP and KC for PCl5?

Answer. KP=KC[RT]power delta N. delta N is gaseous products-gaseous reactants.so 2-1=1.

What happens to the equilibrium PCl5 at constant pressure?

1 Answer. (i) The state of equilibrium remains unaffected.

What is the effect of increasing pressure on the dissociation of PCl5?

When pressure is increased, the equilibrium will shift in the reverse direction so that the effect of increased pressure is nullified. Hence, with increase in pressure, the dissociation of PCl5 is suppressed and the degree of dissociation of PCl5 decreases.

What is the equilibrium constant PCl5 PCl3 Cl2?

(Assume the reaction proceeds from left to right to establish equilibrium. PCl5 PCl3 + Cl2 Is 33.3 at 760 ˚C.

How do you calculate the equilibrium constant?

In this example they are not; conversion of each is requried. Substitute each concentration into the equilibrium expression and calculate the value of the equilibrium constant.

	N2O4	NO2
Equilibrium Pressure (atm)	3.476	1.048

What is the equilibrium partial pressure of PCl5?

2.29 atmospheres

Therefore, the equilibrium partial pressure of PCl5 is 2.29 atmospheres, for PCl3, it’s 1.40 minus x, 1.40 minus 0.33 is equal to 1.07. Therefore, the equilibrium partial pressure of PCl3 is equal to 1.07 atmospheres.

Why does PCl5 dissociate on heating?

Pcl5 has a trigonal pyramidal shape. The bond pair – bond pair repulsion is greater in the two axial P-Cl bonds as compared to the three equatorial P-Cl bonds. So the axial P-Cl bonds are less stable and are removed readily when PCl5 is heated.

What happens when PCl5 reacts with water?

Hydrolysis. In its most characteristic reaction, PCl₅ reacts upon contact with water to release hydrogen chloride and give phosphorus oxides.

How does PCl5 break the octet rule?

Re: Why does PCl5 break the Octet Rule? Phosphorous, Chlorine, and Sulfur can accommodate more than eight electrons and therefore break the octet rule because they contain a 3d orbital.

Does PCl5 undergo hydrolysis?

We know when PCl5 undergoes hydrolysis it forms POCl3 which further hydrolys to give H3PO4.

What is the balance equation of reaction of PCl5 with water?

Overall Reaction: PCl5+4D2O→D3PO4+5DCl.

What happens when PCl5 heated?

Therefore when PCl5 is heated strongly it decomposes to form PCl3.

Asked by: Joshua Thomaz

This is simply because oil and dirt suppress the amount of foam your shampoo creates, so the first time you wash there will be less foam since your hair has more dirt and oil on it. The second time you wash there is less oil in your hair (since it’s already clean!), which also means more foam.

What happens when you shampoo twice?

“Shampooing your hair twice is beneficial because it allows for proper cleansing, giving you longer periods of time with a clean scalp and keeping away the oily hair problem,” he says. “It also keeps you away from over-shampooing your hair, which is a mistake that most women make.”

Should you lather twice?

“Wet the hair, then wash it twice with a non-sulphate shampoo. The first shouldn’t create much lather but the second one will give a lot more,” he explains to The Independent. Florey says it’s essential to shampoo twice, rinsing in between, and your hair will be transformed if you do.

Why do you lather rinse and repeat?

The second shampoo lathers and ensure that there’s nothing left over, so the hair is really clean.” If you don’t shampoo twice, the hair doesn’t get fully clean; it’ll get oily faster, and you won’t get the healthy natural shine of clean hair.

Are you really supposed to lather rinse and repeat?

“Shampoo, rinse, repeat” is just an advertising trick, so you use more shampoo! You’ve known this all along. You don’t actually need to wash your hair twice. Marketers and manufacturers want you to, though.

What is double shampooing?

Double shampooing is a process where you wash your hair with product twice in the same showering session. This method is especially good for women who have overly oily scalps, but dry ends. It should also be the go-to method of cleansing your hair if you tend to use a lot of styling and hair care products.

How many times should I shampoo my hair?

For the average person, every other day, or every 2 to 3 days, without washing is generally fine. “There is no blanket recommendation. If hair is visibly oily, scalp is itching, or there’s flaking due to dirt,” those are signs it’s time to shampoo, Goh says.

How often should you shampoo twice?

Which brings us back to the once or twice debate? “If you’re shampooing every day to every other day, there’s no need to shampoo twice. However, if you shampoo less than three times a week, you should double cleanse.”

Should I shampoo twice if I have dandruff?

As symptoms improve, you may use dandruff shampoos less frequently. Hair washing method is important in treating dandruff. Lather the hair twice and on the second lather, leave the shampoo on the hair for five minutes (or as directed on the shampoo label) before rinsing to give the medicine time to work properly.

Can you use 2 shampoos at once?

Shampoo often strips the natural oils from the hair and putting 2 applications of shampoo on will do more harm than good. If you want the benefits of both shampoos, it’s better to wash one day with one, then about 2 days later when you wash your hair again, use the other one. And always follow with a good conditioner.

Can I wash my hair 2 days in a row?

In general, shampooing your hair every day is not inherently bad. It doesn’t damage your hair, it doesn’t damage your scalp.

Can the wrong shampoo cause dandruff?

What happens with the wrong shampoo? Using the wrong shampoo could make your dandruff appear worse. As a dandruff sufferer, if you don’t use a shampoo that’s clinically proven to help get rid of dandruff, the problem could escalate and flakes could build up.

When should the shampooing process be repeated?

Shampooing and conditioning

Question	Answer
When should you repeat the shampooing process?	When the hair is very dirty or greasy , or to remove a build up of products.
Why is it important to read and follow manufacturers instructions?	To use the products correctly and to get the best result.

Is it OK to wash hair once a week?

If they are dry, it’s fine to wash it once a week, but once a week at least for hygienic purposes,” Dr. Fusco says. (She clarifies that this is because product can build up on the scalp, potentially leading to clogged pores, irritation, or flakes.)

Should you shampoo the ends of your hair?

You don’t need much (if any) shampoo on the tips of your hair. “The truth is that you have to focus on shampooing your scalp, rather than the ends of your hair,” Davis says. “Apply shampoo only onto the scalp, and let it clean the rest of the hair when you rinse it out.”

Should you shampoo everyday?

In fact, you should not shampoo every day. The exact number depends on your hair, but think more like two or three days a week. Shampooing removes oil. And it’s totally logical to think that shampooing more would mean less oil—totally linear.

Is it OK to shampoo twice a day?

“If you’re a daily washer then there’s no need to double cleanse (AKA shampoo twice),” says Anabel. “I only say shampoo twice after using Elasticizer or lots of hair products, and only if you have fine hair or only wash your hair less than every other day, in which case you should shampoo twice too.”

Do you really need to shampoo twice?

“If you’re shampooing every day to every other day, there’s no need to shampoo twice. However, if you shampoo less than three times a week, you should double cleanse.”

Can you use 2 shampoos at once?

Shampoo often strips the natural oils from the hair and putting 2 applications of shampoo on will do more harm than good. If you want the benefits of both shampoos, it’s better to wash one day with one, then about 2 days later when you wash your hair again, use the other one. And always follow with a good conditioner.

How often should you double shampoo your hair?

If you’re just taking double shampooing for a spin, start with 1-2 washes per week and see how your hair responds. A haircare routine where hair is washed daily or every other day can often result in over-productive oil glands, and it may take some time to retrain your scalp to ease back into balance.

How do you properly shampoo?

So, what are the correct hair washing steps to follow?

1. Wet your hair thoroughly. Don’t jump straight into applying your shampoo. …
2. Apply your shampoo. Remember: This shampoo should be the right kind for your hair. …
3. Go easy on your scalp. …
4. Rinse thoroughly. …
5. Apply conditioner. …
6. Rinse again. …
7. Dry.

Should you shampoo the ends of your hair?

“Shampoo is made to clean the scalp, so that should always be your focus in the shower — not shampooing from top to ends. The lather in your shampoo should be strong enough to clear out any residue on the ends when you are washing it out,” said Marc Mena, who works with Chrissy Metz, Mindy Kaling and Katie Lee Gifford.

Asked by: Margaret Griffin

How do you calculate the ionic strength of a solution?

Multiply the squared charge numbers by the ionic concentration. Add up all the products of the ionic concentration and charge numbers. Divide the sum value by 2. The result is the ionic strength of the solution as mol/kg of solute or mol/L of solution.

What is the ionic strength of a solution containing 0.15 M NaCl and 0.25 m CaCl2?

Question: What is the ionic strength of a solution containing 0.15 M NaCl and 0.25 M CaCl2? The answer is 0.775 M BUT what are the steps to obtain that answer?

How do you find the ionic strength of 0.2 M na2hpo4?

This is Expert Verified Answer



Ionic strength of the solution is known as the function of all Ion present in solution. Hence Ionic strength = 0.6 M.

How do you calculate the ionic strength of 0.1 M KCl?

ionic strength of the solution. Problem: Calculate the ionic strength of the solution that is 0.1 mol/kg in KCl(aq) and 0.2 mol/kg in CuSO₄(aq). I = I(KCl) + I(CuSO₄) = 1/2(1×1 + 1×1)(b/b⁰)(KCl) + 1/2(1×2²+1×2²)(b/b⁰)(CuSO₄) = 0.1 + 4×0. 2 = 0.9.

How do you calculate the ionic strength of cacl2?

Note the stoichiometric factor 2 of Cl^– in the second line. Based on this equation, a 0.5 molar CaCl₂ solution has an ionic strength of I = 3 × 0.5 M = 1.5 M.

How do you determine the strength of a solution?

Strength of solution = Mass of solute ( g ) Volume of solution ( L )



Strength or concentration:

1. The strength of the solution is defined as the amount of solute in gram dissolved per liter of the solution.
2. It represents the strength or concentration of the solution.
3. It expresses in grams per liter.

What is the ionic strength of 0.01 m NaCl solution?

Ionic strength of a solution made by mixing equal volumes of 0.01 M NaCl and 0.02 M AlCl3: 0.065 CORRECT ANSWER 0.13 0.0325 0.0216.

Which is the ionic strength of 0.25 MK so solution?

SOLVED: The ionic strength for 0.25 M K2SO4 is: 0.75 m 0.63 m 06 m 0.07 m.

What is the ionic strength of 0.1 M cuso4 solution?

1×3×22]=0. 19.

How do you find the ionic strength of Na2SO4?

Equation 1: I = 0.5∑(cizi 2 ) (b) Predict whether the ionic strength of 0.2 M Na2SO4 would be higher or lower than the value calculated in part (a) if the association Na+ + SO4 2- = NaSO4 – was taken into.

What is the ionic strength formula identify the variables?

General formula: The ionic strength formula is calculate as the sum of the molar concentration of each ion multiplied by the valence squared. where the term 1/2 is due to both ions are considered (cation and anion), c is the concentration in molar units (mol/L) and z is the charge of each ions.

What is the ionic strength of 0.2 Molal bacl2?

Answer: 0.6 mol/L is the ionic strength of BaCl₂.

How do you calculate the ionic strength of seawater?

The ionic strength of seawater is approximately 0.7: I = ^ ([Cl~] x 1 + [Na+] x 1 + [Mg2+] x4 + [S02~] x4 + …) « 0.7 , which corresponds to a seawater salinity of S ~ 35. The ionic strength of seawater may be calculated from salinity by (DOE, 1994):

What is ionic strength of a buffer?

The formula in Step 1 states that ionic strength is a squared sum of concentrations and valences of all ions in the solution. Allow the molar concentration of ions to be represented by “C.” In mixed solutions, there will be several concentrations to sum. The unit is moles per liter for all ions.

What does ionic strength measure?

Ionic strength is typically calculated as the product of a given ion’s concentration, ci, and its charge, zi, summed over all ions in solution, divided by two (IUPAC Quantities, Units and Symbols in Physical Chemistry, 1993), and measured either as mass per unit volume (i.e., mg/L) or in moles (i.e., mmol/L).

What is ionic strength in chemistry?

The ionic strength of a solution is the amount of ion concentration in it. It’s written in the form of I. It has an impact on ion activity. The ion interaction with water and other ions in the solution is marked. The ionic strength formula is used to calculate half of each ionic species’ total concentration.

How do you calculate the ionic strength of seawater?

The ionic strength of seawater is approximately 0.7: I = ^ ([Cl~] x 1 + [Na+] x 1 + [Mg2+] x4 + [S02~] x4 + …) « 0.7 , which corresponds to a seawater salinity of S ~ 35. The ionic strength of seawater may be calculated from salinity by (DOE, 1994):

What is the ionic strength formula identify the variables?

General formula: The ionic strength formula is calculate as the sum of the molar concentration of each ion multiplied by the valence squared. where the term 1/2 is due to both ions are considered (cation and anion), c is the concentration in molar units (mol/L) and z is the charge of each ions.

Which is the ionic strength of 0.25 MK so solution?

SOLVED: The ionic strength for 0.25 M K2SO4 is: 0.75 m 0.63 m 06 m 0.07 m.

What is the molarity of Na+ ions in a 0.20 m Na2CO3 solution?

0.40 M

Answer and Explanation: The molarity of Na+ ions in a 0.20 M Na2CO3 N a 2 C O 3 solution is equal to 0.40 M. From this equation, we can see that one mole of the compound produces two moles of Na+ ions.

What is the ionic strength of 0.2 Molal bacl2?

Answer: 0.6 mol/L is the ionic strength of BaCl₂.

Asked by: Margaret Griffin

What is work non expansion?

Non expansion work is all other work like electrical, frictional, mechanical etc. There is no fixed formula for determination of non-expansion work.

What is non expansion work in chemistry?

Expansion work is pressure-volume work, and nonexpansion work is anything else (electrical, friction, motional, etc.) Expansion work is always given by w=-P_ext*dV while there is no fixed formula for the nonexpansion work. However, the Gibbs free energy gives the maximum amount of nonexpansion work that could be done.

What is meant by expansion work?

1 the act of expanding or the state of being expanded. 2 something expanded; an expanded surface or part. 3 the degree, extent, or amount by which something expands. 4 an increase, enlargement, or development, esp. in the activities of a company.

Why is non expansion work called useful work?

Non-expansion means not related to a volume change, for example, electrical work, which is also what we call “useful work”. This can be proven mathematically using differentials, which we do NOT have to know for this class.

What does non expansion mean?

Related Definitions



Non-Expansion means the Replacement, Upgrade or Rehabilitation of a component of the ARWA System.

Why is shaft work negative?

Thus the sign of shaft work is always negative, work being done on the system by the surroundings. Shaft work can hardly be done indefinitely slowly; consequently it always produces entropy within the system, because it relies on friction or viscosity within the system for its transfer.

What is pressure-volume work?

Pressure–volume work is the work that is done by the compression or expansion of a fluid. Whenever there is a change in volume and external pressure remains constant, pressure–volume work is taking place.

What is work done in thermodynamics?

In thermodynamics, thermodynamic work is the quantity of energy transferred from one system to another. It is a generalization of the concept of mechanical work in mechanics. In the SI system of measurement, work is measured in joules (symbol: J). The rate at which work is performed is power.

How does Gibbs free energy relate to work?

The Relationship between ΔG and Work



The change in Gibbs energy is equal to the maximum amount of work that a system can perform on the surroundings while undergoing a spontaneous change (at constant temperature and pressure): ΔG=wmax.

What is expansion example?

Expansion is defined as the act of getting bigger or something added onto something else. An example of an expansion is an extra three rooms built onto a house. noun.

Is expansion work positive?

Work done by a system (as the system expands) has a negative value. Work done on a system (as the system shrinks) has a positive value.

How do you calculate expansion work?

Steps for Calculating Work Done by an Expanding Gas



Step 1: Identify the pressure of the gas. Step 2: Identify the change in the volume of the gas. Step 3: Find work done by gas by substituting the values found in steps 1 and 2 into the equation for pressure-volume work W=pΔV W = p Δ V .

What is the difference between expansion and non expansion states?

In particular, Medicaid expansion states have more policies addressing immigrant eligibility to their Medicaid programs, as opposed to nonexpansion states.

What is the purpose of Medicaid expansion?

Medicaid expansion drives gains in health coverage among people who were previously eligible for Medicaid, including children and parents. Most children in families with low incomes were eligible for Medicaid before the ACA, but Medicaid eligibility for parents was limited and varied considerably across states.

What is Medicare expansion mean?

Non-expansion Work

What is expansion in short answer?

Expansion is the process of becoming greater in size, number, or amount.

What is expansion and contraction?

Thermal Expansion and Contraction. THERMAL EXPANSION AND CONTRACTION. Materials expand or contract when subjected to changes in temperature. Most materials expand when they are heated, and contract when they are cooled. When free to deform, concrete will expand or contract due to fluctuations in temperature.

How do you write an expansion?

Format of Expansion of ideas

1. Title.
2. Introductory paragraph.
3. Core content.
4. Concluding paragraph.

What is the meaning of expansion in mathematics?

Expansion is an affine transformation (sometimes called an enlargement or dilation) in which the scale is increased. It is the opposite of a geometric contraction, and is also sometimes called an enlargement. A central dilation corresponds to an expansion plus a translation.

How do you expand a number in math?

Here are the steps to write a number in expanded form.

1. Get the number in its most basic form.
2. Using the place value chart, determine its place values.
3. Multiply the number by the number’s place value.
4. Display it as a digit place value.
5. All digits should be represented as the product of the digit and its place value.

Asked by: Hendika Soto

When should you use an oil bath?

An oil bath is a type of heated bath used for laboratories, it is the most common for heating chemical reactions. It is most commonly used in research laboratories for reactions that require heating temperatures up to 200 degrees Celsius. Oil baths provide more uniform heat compared to other heaters.

What is the reason for using oil bath rather than a water bath?

Oil baths are much like water baths, but use silicone or mineral oils in order to enable temperatures hotter than the boiling point of water (> 100oC).

Why is it better to use a sand bath for heat?

Sand baths have a number of advantages compared with simply using a hotplate. This includes: Heat is conducted directly into the sides of the heated vessel. Because of this the vessel is heated a lot more evenly than if the heat source was only coming from below.

What is the difference between sand bath and water bath?

Answer. Answer: Water baths, heated on a hotplate, are most commonly used to heat solutions to 100oC (boiling baths, Figures 1.53 + 1.54a). … Sand baths, also heated on a hotplate, can be used to heat solutions to a wide variety of temperatures, including very high temperatures (> 250oC).

When we should not take oil bath?

It is also ideal to have the oil bath in the morning , on an empty stomach, before 9-10 AM. This gives the body the complete day to gently reset the doshas. Therefore oil bath should be avoided in the evenings.

What is the benefit of sand bath?

Sweating detoxifies the body, and the sand grains exfoliate dry skin. The weight of the sand helps to relax the muscles and quiet the mind. Due to the sand’s mineral composition, sand hammams are also used to combat skin conditions, such as acne, psoriasis and other medical ailments.

What is oil bath method?

An oil bath is a type of heated bath used in a laboratory, most commonly used to heat up chemical reactions. It’s essentially a container of oil that is heated by a hot plate or (in rare cases) a Bunsen burner.

Which water is good for oil bath?

warm water

Use warm water to bathe.

Why oil bath is used in fractional distillation?

To avoid direct heating of the reaction mixture during fractional distillation, we keep it in an oil bath. As a result, an oil bath is required to control the temperature of the mixture that needs to be separated.

Why is sand bath is used in evaporation?

It is set up like the water bath but it is able to maintain a higher heat than the water or ashes. Many oils and substances with boiling points higher than water can be heated and distilled with the sand bath. It provides and even heating of the matter and avoids hot spots from developing.

Can humans take sand baths?

Used as a natural therapy, a sand bath isn’t only relaxing. Thought to have similar effects to a sauna, in that it cleanses the body and helps to remove toxins through sweating, the sand bath has the added benefit of the weight of the hot sand pressing down on the body to help loosen muscles too.

Why use water bath in heating the solution instead of heating it directly on the hot plate?

Often a reaction mixture needs to be heated for a certain time for the reaction to happen. Heating directly on a Bunsen burner or on a hot plate is not uniform heating is associated with fire hazards. Heating the reaction mixture indirectly in a water bath achieves uniform heating with less fire hazard.

Do and don’ts after oil bath?

After oil bath, one should rest for the day and avoid the following: strong sun, cold water, yoga or heavy work of any kind. For men, tradition prescribes that oil bath be taken on Monday, Wednesday or Saturday.

Can we take oil bath during cold?

But a cold, cough, or the flu may lead to symptoms including muscle aches and soreness, and detox baths may help with these symptoms. Adding essential oils, such as lavender and chamomile, to your bath may have some benefits for cold symptoms. That’s because essential oils may help you relax and calm down.

Can we take oil bath on rainy day?

2. Avoid oil bath during rainy days – don’t sleep during the day after taking oil bath.

Should I apply oil before or after shower?

Here’s a handy little trick for applying the oil: we always recommend applying the oil to skin that is still damp or wet. In other words, right after you get out of the shower after blotting off any excess water with a towel, or even while you are still in the shower.

Do you oil hair before or after shower?

Use a hair oil on your scalp and strands before you shower and while in the shower for a deep moisturizing treatment.

Is it OK to sleep after oil bath?

Avoid oil bath during rainy days – don’t sleep during the day after taking oil bath. Sleep will further lower the body tempera- ture and you may get sick (but not neces- sarily). 3. After taking bath, dry the hair in the open sun (for a few minutes) if possible or under the fan.

Is it good to take oil bath daily?

Reportedly, applying body oil before your shower leads to multiple health benefits. The skin is the largest organ of the body and according to Ayurveda, it is recommended to perform Abhyangam or oil application daily. In ancient times, Indian used to oil their body first and then go for bathe in the lake or wells.

Is an oil bath good for your skin?

Strengthens the immune system to fight bacterial and fungal infections. Improves blood circulation by dilating blood vessels. Reduces fatigue and stiffness in joints. Keeps the skin collagen supple, resulting in fresh, glowing skin.

Do and don’ts after oil bath?

After oil bath, one should rest for the day and avoid the following: strong sun, cold water, yoga or heavy work of any kind. For men, tradition prescribes that oil bath be taken on Monday, Wednesday or Saturday.

Asked by: Hendika Soto

What is the most effective thermal insulator?

aerogel

The best insulator in the world right now is most probably aerogel, with silica aerogels having thermal conductivities of less than 0.03 W/m*K in atmosphere. of aerogel preventing ice from melting on a hot plate at 80 degrees Celsius! Aerogel has its amazing properties because it’s mostly made out of air.

What are the types of thermal insulation?

Types of Insulation

Type	Material
Foam board or rigid foam	Polystyrene Polyisocyanurate Polyurethane Phenolic
Insulating concrete forms (ICFs)	Foam boards or foam blocks
Loose-fill and blown-in	Cellulose Fiberglass Mineral (rock or slag) wool

Which material is typically used as a thermal insulator?

Some common materials used as thermal insulators include fiberglass, cellulose, and polystyrene.

Which material is the best heat insulator?

Plastic, rubber, wood, and ceramics are good insulators. These are often used to make kitchen utensils, such as saucepan handles, to stop heat from flowing up to burn the cook’s hand. Plastic coating is also used to cover most electrical wires in appliances.

What is the most cost effective insulation?

Fiberglass is a low-cost option for insulation. You can choose either to install it yourself or to have it professionally installed. Fiberglass batts are available in a variety of lengths and thicknesses, depending on your needs. They range in price from $0.50 to $1.50 per square foot.

Is wood a good thermal insulator?

Wood is a natural insulator. Wood has a lower thermal conductivity compared to concrete, steel-frame and masonry construction and is ideally suited to energy-efficient design. As a natural insulator, it provides some of the world’s coldest climates with warm and comfortable dwellings.

Is foam a good heat insulator?

Polystyrene and plastic foam are both used as insulators as they have small air bubbles trapped inside them. This makes them very good insulators because heat energy can’t flow through them.

What type of insulation should I use?

Depending on where you live and the part of your home you’re insulating (walls, crawlspace, attic, etc.), you’ll need a different R-Value. Typical recommendations for exterior walls are R-13 to R-23, while R-30, R-38 and R-49 are common for ceilings and attic spaces.

What’s the best insulation for walls?

The best insulation for walls when it comes to new build homes or remodels is going to be Nu-Wool, foam board, or open cell spray foam.



Cons:

• Open cell spray foam is an expensive option for insulation.
• Spray foam can’t be installed as a DIY project.
• Some brands of spray foam have an odor when installed.

Is there a perfect thermal insulator?

A perfect insulator, or a material that reflects heat while absorbing none of it, has been created by scientists at the Massachusetts Institute of Technology and Sandia National Laboratories. Besides eliminating your heating bill, perfect insulators could make computers cooler and speed up cell phone downloads.

Is bubble wrap a good insulator?

Bubble wraps serve as a good insulator because of its design which has small air pockets. Because the base material for bubble wraps are plastic, it heats up quickly, and so bubble wraps serve as good insulators.

What are the 4 main types of insulation used in homes?

There are several different types of insulation, including the four most common listed below:

• Loose-Fill & Blown-In Insulation.
• Batt & Roll Insulation.
• Reflective Insulation & Radiant Barriers.
• Spray Foam & Foam-In-Place Insulation.

How can I insulate cheaply?

5 DIY Ways to Insulate Your Home on the Cheap

1. Cover any air leaks with weatherproofing. Use weatherproofing strips and caulking to seal any air leaks in your doors and windows. …
2. Add thick curtains to your windows. …
3. Fix drafty doors with a door snake. …
4. Plug your chimney when not in use. …
5. Seal your attic air leaks.

What is the cheapest most efficient insulation?

Cheap Insulation Alternatives



Unfortunately, if you’re looking to save money with your home’s insulation, fiberglass is by far the most cost-effective solution. But it’s important to consider how much money you’ll be paying in energy costs if your insulation isn’t up to snuff.

What’s the cheapest way to insulate your house?

Quote from video: Just take an unphased insulation a roll it right on top and that one step there make it home much more energy-efficient.

What metal is the best thermal insulator?

Which Metals Conduct Heat The Best?

Common metals ranked by thermal conductivity
Rank	Metal	Thermal Conductivity [BTU/(hr·ft⋅°F)]
1	Copper	223
2	Aluminum	118
3	Brass	64

What is a better insulator than Styrofoam?

It is called nanowood. It blocks heat at least 10 degrees better than Styrofoam or silica aerogel. Silica aerogel is a common insulator. And nanowood can take at least 30 times more pressure before being crushed.

Is aerogel the best insulation?

Air in microscopic pores make up the remaining 97% of aerogel’s volume. This air has very little room to move, inhibiting both convection and gas-phase conduction. These characteristics make aerogel the world’s lowest density solid and most effective thermal insulator.

What are the downsides of aerogel?

Disadvantages: Increased density (typically about one-third to one-half the density of water) Decreased clarity (from translucent to foggy to opaque) Decreased surface area (by about half)

Why is aerogel not used for insulation?

Such factors make Aerogel very light, making mass conduction impossible. Secondly, Aerogel has extremely tiny pores, typically between 2-50 nm in diameter. These pores are so small that it is difficult for the air to diffuse through the material and transfer the convective heat.

Asked by: Rob Blake

Muriatic acid is a powerful and corrosive acidic liquid made from hydrochloric acid, water, and other trace minerals. This product is a very strong acid that will clean dried cement products off stones, bricks, and other masonry surfaces.

How do you remove limewash from brick?

Surface stains on limewashed brick can be removed by rubbing lightly with a damp rag. Limewash coating can be removed with a pressure washer, or by hand, with a bucket of water and a stiff nylon scrub brush if you grow tired of the look.

Does vinegar remove limewash?

Clean up is easy. Just wash your brush and equipment with soap and water. Drips or splatters are easy to wipe off with a wet rag. Once Limewash is fully dry it is more stubborn to remove, but scrubbing with a little vinegar does the trick.

Can you reverse limewash brick?

Limewash can easily be removed from bricks. If you want to change the look of your brick walls, you can remove the limewash with the use of a stiff brush or a pressure washer. Moreover, the limewash can slowly dissolve using an acidic cleaner. However, the process can be time-consuming since it needs to be reapplied.

Is limewash easy to remove?

Like cement mortars, it can be very slowly dissolved with an acidic cleaner like Aciclean but the process is extremely time-consuming, as the product has to be continually re-applied. Removal is therefore only practicable if the limewash is very thin.

Can you un whitewash brick?

Yes, it is possible for you to remove whitewash from brick or stone by yourself. There are special paints and solutions that can help you strip whitewash from the outside of your building. It can take a long time for you to remove whitewash, particularly if it covers the entirety of your building.

Is limewash on brick permanent?

After you apply limewash to a brick wall or brick house, it calcifies into the brick’s surface, it’s protected from moisture buildup. It isn’t permanent and you can use lime wash brick on any home.

What Dissolves lime build up?

Two of the most effective substances are lemon juice and ordinary vinegar. Lemon juice is usually the best (and will also leave a lovely smell behind). Stronger pickling vinegar and lime juice are both even more acidic and can be used for really stubborn deposits.

What will dissolve lime?

Use a solution with water, of either white vinegar, an acetic acid, or lemon juice, a citric acid, to dissolve lime. Start with a 25 percent — up to a 50 percent solution for thick layers — and scrub hard container surfaces such as plastic or enamel with a dish brush, and then rinse well to remove deposits.

Will baking soda and vinegar remove lime?

Dip a scouring pad or brush into vinegar and then baking soda. Scrub the surface to remove any lime buildup. Reapply the baking soda and vinegar to the scouring pad as necessary.

Does acetone remove paint from brick?

Does Acetone Remove Paint From Brick? Acetones versatile nature means you can use it to remove paint and clean paint off of other surfaces, too, including brick. Acetone is an environmentally friendly option for removing paint from brick and does a decent job.

How do you remove lime paint from stone?

water washing: including gentle sponging or scrubbing with a soft bristle brush may be effective for emulsions, limewash, and other very old, friable paints. steam stripping: superheated low-pressure steam stripping for water-thinned paints, such as emulsions, can clean without saturating the surface of the stone.

Can I paint over limewash brick?

“The process gets a bit trickier if you are working in a room with coved ceilings or stair-walls.” And for all those renters out there wondering if you can easily paint over limewash, you’ll be pleased to know that you can.

Does WD 40 Remove paint brick?

Does WD-40 remove paint brick? WD-40 may be able to help you out with dried paint stuck in the crevices of your brickwork. Spray the WD-40 on the paint and use a stiff brush to scrub any stubborn areas.

What’s the difference between whitewash and limewash?

Whitewash is taking a watered down version of paint and applying it directly to the brick. The whitewash sits on top of the brick. Limewash is a mix of lime, minerals, and water that is applied directly to the brick. Limewash soaks into the brick instead of sitting directly on top of it.

How do you remove whitewash?

One method that you can use is to dilute white vinegar with water using a 1:1 ratio to create a solution. Use a rag or sponge to wipe the surface of the material where you would like to remove the whitewash. If the whitewash is made from diluted paint, you can use a paint stripper to remove paint runs.

Does limewash wash off?

One beauty of limewash is it’s removable, within a few days, if you change your mind. Every time limewash is applied it’s going to look differently depending on who is applying and how it is washed off to create the antique effect.

Can you paint over limewash brick?

What is this? — You can paint over top of a limewash paint job, but you will need to use a mineral primer. — If you’re painting in a high-traffic area, you can seal the paint with an interior and exterior sealer for easier cleaning.

How do you remove white paint from brick?

If there’s still paint remaining on the brick, then spot treat with a paint remover or paint stripping gel. Then using a scrub brush with a back-and-forth motion, continue to scrub the brick to remove paint that has set deep into the pores of the brick.

Why is my limewash turning yellow?

I have yellow, rust colored stains seeping through. What did I do wrong? Those are most likely tannin-related stains coming through your bricks. You could go over those areas with Romabio MicroGrip Primer, then another coat of Classico Limewash to both help block the tannins and touch up the stained areas.

Will limewash come off in rain?

If properly applied, limewash will not come off in rain. After it has dried, limewash becomes highly water-resistant. This is why it can be used outdoors. Once you have applied the limewash to your outdoor walls, allow it to thoroughly dry for up to four hours.

How do you paint over lime wash?

“A coat of special primer is needed before painting over it with regular paint, or you can paint over it with chalk-based paint and skip the primer,” says van Os.

Asked by: Rob Blake

Is lithium grease safe on plastics?

Lithium-based lubricants are used in cars and machinery in general. It’s not advisable to use them on plastic parts. As lithium is based on petroleum, it tends to speed up rubber and plastic components decay.

What grease is best for plastic?

Lubricants based on silicone, perfluorinated PFAE, mineral oils, and synthetic hydrocarbons (SHC or PAO), typically work well with plastics. Esters and polyglycols are generally not compatible with plastic, although there are exceptions based on the type of plastic material.

Does grease corrode plastic?

It is true that some lubricants (both mineral and synthetic based) can cause plastics and elastomers to swell or crack over time. The swelling, cracking and even discolouration are not instant and can take many hours of exposure to the grease for the damage to occur.

Which is better silicone or lithium grease?

As mentioned above, and unlike lithium grease, silicone lubricant is the perfect lubricant for rubber surfaces, but it is also extremely versatile, so it can be used on most other materials, including metal, plastic, wood, and even painted materials.

What can I use to lubricate plastic gears?

Typically, lubricants based on silicone, PFAE (perflourinated), most synthetic hydrocarbons (SHC or PAO), or mineral oils work well with plastics.

Is white lithium grease safe for plastic gears?

The answer is: yes, it is by far the best lubricant for nylon gears. No, it will not do anything bad to your gears. White lithium grease works perfectly with nylon gears. People have been using it for lubricating RC servo gears for forever.

What’s the difference between lithium grease and regular grease?

They have better water resistance properties compared to sodium soap greases, better high-temperature properties compared to calcium soap greases, and excellent mechanical properties (both resistance to shearing and good ability to be pumped).

What is lithium grease good for?

On that note, White Lithium Grease is ideal for long-term lubrication, vertical applications, and where the prevention of water ingress is a requirement. What’s more, it can also be used as a break-in lubrication for bearings, pistons and camshafts. Other notable applications include: Door hinges.

Is WD-40 safe on plastic?

WD-40 can be used on just about everything. It is safe for metal, rubber, wood and plastic. WD-40 can be applied to painted metal surfaces without harming the paint. Polycarbonate and clear polystyrene plastic are among the few surfaces on which to avoid using a petroleum-based product like WD-40.

Is silicone grease good for plastic?

In lubricants, a silicone base oil is commonly used in greases for plastic gears, control cables, and seals because they are inert, compatible with most plastics and elastomers, and remain stable over a wide temperature range.

Is vaseline a good lubricant for plastic?

Can vaseline be used as a lubricant? Ans. Vaseline or petroleum jelly is compatible with plastics but won’t give ideal results. Even if you go with it checking its chemical compatibility with plastic is advised.

Can I use lithium grease on brake calipers?

White lithium is a low-temperature grease that can be used to lubricate drum brake hardware and backing plates, but lacks the heat-resistance for front disc brake applications. So this type of grease is not the best choice for general brake work.

What is the best lubricant for rubber seals?

The solution is: Use silicone lubricant for o-rings and seals to be safe. Silicone lubricant is waterproofing and lubricating. It costs $10 for a small tube and is available at all auto parts stores. Be safe, use silicone grease on your o-rings and rubber seals in pressure washer wands, hoses and pumps.

Should plastic gears be greased?

Most plastic gears are capable of running without lubrication or can be embedded with lubricating materials (such as graphite, silicone, or PTFE). However, some operating conditions benefit from, or even require, lubrication.

Where should you not use silicone grease?

Because it is so slippery and persistent, avoid using silicone spray under the following conditions:

1. DO NOT USE SILICONE SPRAY ON ELECTRICAL CONNECTIONS, SWITCHES, RELAYS, ETC. …
2. On any surface upon which you walk, sit, or lay.

Is Teflon grease safe on plastic?

Lubricants with silicone or PTFE (polytetrafluoroethylene) are best for use on plastic surfaces. PTFE is hydrophobic, meaning it repels water, so lubricants containing it are effective in damp conditions.

Can I use dielectric grease on plastic gears?

Quote from video: So if you're ever looking for a grease to put on plastic to be able to lubricate it make these come off a little bit easier just any plastic part silicone grease will work it's not petroleum-based.

Is WD 40 safe for plastic?

WD-40 can be used on just about everything. It is safe for metal, rubber, wood and plastic.

Can I use WD 40 on plastic gears?

WD40’s low viscosity, cleaning, and degreasing composition will inevitably cause deep penetration to plastic. Although it may also be used to clean surfaces covered with dirt, grease, and even grime, WD40 will leave excess oil streaks on plastic which can be difficult to remove.

Can you use silicone grease on plastic?

In lubricants, a silicone base oil is commonly used in greases for plastic gears, control cables, and seals because they are inert, compatible with most plastics and elastomers, and remain stable over a wide temperature range.

Is vaseline a good lubricant for plastic?

Can vaseline be used as a lubricant? Ans. Vaseline or petroleum jelly is compatible with plastics but won’t give ideal results. Even if you go with it checking its chemical compatibility with plastic is advised.

Where should you not use silicone grease?

Because it is so slippery and persistent, avoid using silicone spray under the following conditions:

1. DO NOT USE SILICONE SPRAY ON ELECTRICAL CONNECTIONS, SWITCHES, RELAYS, ETC. …
2. On any surface upon which you walk, sit, or lay.

Does baby oil corrode plastic?

Baby oil can degrade materials used in sex toys



Baby oil shouldn’t be used with sex toys made from latex, silicone, rubber, or plastic. Petroleum can degrade these materials and turn your sex toys into a horrible mess.

Asked by: Jennifer Newhouse

How do you derive the Arrhenius equation?

The Arrhenius equation is sometimes expressed as k = Ae^–E/RT where k is the rate of chemical reaction, A is a constant depending on the chemicals involved, E is the activation energy, R is the universal gas constant, and T is the temperature.

What is Arrhenius theory of collision?

As per the Arrhenius Equation, all the molecules that have energy greater than or equal to activation energy will collide to form products. But this postulate was not true for all the reactions. A significant amount of deviation was observed in reactions involving complex molecules.

What is collision frequency in Arrhenius equation?

It is also called the frequency factor and describes how often two molecules collide. To first approximation, the pre-exponential factor is considered constant. for deriving the collision frequency, Z between A and B.

What is hard sphere collision theory?

[′härd ‚sfir kə′lizh·ən ‚thē·ə·rē] (physical chemistry) A theory for calculating reaction rate constants for biomolecular gas-phase reactions in which the molecules are considered to be colliding, hard spheres.

Which of the following is Arrhenius equation?

k=Ae−Ea/RT represents Arrhenius equation.

How do you calculate EA in chemistry?

Activation Energy Problem

1. Step 1: Convert temperatures from degrees Celsius to Kelvin. T = degrees Celsius + 273.15. T₁ = 3 + 273.15. …
2. Step 2 – Find E_a ln(k₂/k₁) = E_a/R x (1/T₁ – 1/T₂) …
3. Answer: The activation energy for this reaction is 4.59 x 10⁴ J/mol or 45.9 kJ/mol.

What is Arrhenius equation and explain the terms involved in it?

Definition of Arrhenius equation



Note: The Arrhenius equation is sometimes expressed as k = Ae^–E/RT where k is the rate of chemical reaction, A is a constant depending on the chemicals involved, E is the activation energy, R is the universal gas constant, and T is the temperature.

What are the 3 parts of collision theory?

There are three important parts to collision theory, that reacting substances must collide, that they must collide with enough energy and that they must collide with the correct orientation.

What are the 4 points of collision theory?

The collision energy must be greater than the activation energy for the reaction. The collision must occur in the proper orientation. The collision frequency must be greater than the frequency factor for the reaction. A collision between the reactants must occur.

How does collision theory explain the rate of chemical reaction?

Collision theory states that the rate of a chemical reaction is proportional to the number of collisions between reactant molecules. The more often reactant molecules collide, the more often they react with one another, and the faster the reaction rate.

How do you explain collision theory?

collision theory, theory used to predict the rates of chemical reactions, particularly for gases. The collision theory is based on the assumption that for a reaction to occur it is necessary for the reacting species (atoms or molecules) to come together or collide with one another.

How do you find the collision frequency factor?

The formula is k=Ae−EaRT k = A e − E a R T where k is the reaction rate constant in a quantity/second, A is the frequency factor in a quantity(collisions)/second, Ea the activation barrier (energy) in Joules/mole, R the universal gas constant (8.314 Joules per Kelvin per mole), and T is the absolute temperature in

What is the unit of A in Arrhenius equation?

A is known as the frequency factor, having units of L mol⁻¹ s⁻¹, and takes into account the frequency of reactions and likelihood of correct molecular orientation. The Arrhenius equation allows us to calculate activation energies if the rate constant is known, or vice versa.

What is the purpose of Arrhenius equation?

The Arrhenius equation can be used to determine the effect of a change of temperature on the rate constant, and consequently on the rate of the reaction. If the rate constant doubles, for example, so does the rate of the reaction.

What is the significance of Arrhenius equation?

Quote from video:

What is k in k AE EA RT?

k = Ae. −Ea. RT. Both A and Ea are specific to a given reaction. k is the rate constant.

How do you find the temperature using the Arrhenius equation?

Quote from video: Then rearrange this and we wind up with the temperature equals negative EA divided by natural log of K minus the natural log of a times our plug.

How do you find k in Arrhenius equation?

Quote from video: Times 1 over t2 minus 1 over T 1. And if we multiply both sides by k1. This is how you can solve for the rate constant k2. So k2 is equal to k1 times e raised to the negative EA over R.

What is Arrhenius equation explain its importance?

The Arrhenius equation describes the relation between the rate of reaction and temperature for many physical and chemical reactions. A common form of the equation is [9]: (6.10) where k=kinetic reaction rate, k₀=rate constant, E=activation energy, R=universal gas constant and T=absolute temperature.

What is Application of Arrhenius equation?

The Arrhenius equation is the appropriate model for predicting parameters according to phase changes, and it can be used to estimate the properties of materials as temperature and energy change (Amasaki et al., 2000; Galwey and Brown, 2002).

What is the unit of A in Arrhenius equation?

A is known as the frequency factor, having units of L mol⁻¹ s⁻¹, and takes into account the frequency of reactions and likelihood of correct molecular orientation. The Arrhenius equation allows us to calculate activation energies if the rate constant is known, or vice versa.

Asked by: Jennifer Newhouse

Which plays a major role in the formation of complex compounds?

Ni(CO)4.

What is formation of complex compound?

such weak bonds is called complex formation—that is, formation of a new chemical species, called a complex, which is held together by weak forces that are chemical in nature rather than physical. Such complexes usually exist only in solution; because of their low stability, they cannot, in general, be isolated.…

What are the factors on which the stability of a complex depends?

There are several factors that can affect the stability of the metal complexes [2, 5, 8, 9], which include:

• Nature of the central metal ion.
• Nature of the ligand.
• Chelating effect.
• Macrocyclic effect.
• Resonance effect.
• Steric effect or steric hindrance.

Why the transition elements form a large number of complex compounds?

Transition elements form a large number of complex compounds due to the comparatively smaller sizes of the metal ions; their high ionic charges and the availability of d-orbitals for bond formation.

How size of cation affect the stability of a complex?

Size of metal ion : As the size of the metal ion decreases, the stability of complex increases.
III. Basic strength : The more basic a ligand, the greater is the ease with which it can donate its lone pair of electrons and therefore, the greater is stability of the complexes formed by it.

How do you know which complex is more stable?

Thermodynamically it is favoured that a complex having monodentate ligand tends to react with either polydentate or bidentate ligands in order to form a chelate complex, as this is driven by entropy. Thus, bidentate or polydentate are considered to be more stable.

How do charge and size of central metal ion affect the lability of complexes?

ii) Charge on the Central Metal Atom: A smaller, more highly charged ion allows a closer and faster approach of the ligands and greater force of attraction. This results in the formation of a stable complex. In general, the greater the charge on the central metal ion, the greater the complex’s stability.

How does the nature of ligand influence the formation and stability of complexes?

Stronger the ligand, more stable will be complex. Polydentate ligands form more stable complex than unidentate ligand. If multidentate ligand is cyclic, it further increases the stability, it is called macrocyclic effect.

Why chelate complexes are more stable?

Solution : Chelating complex is more stable than unchelated complex because the ligand is attached to the metal ion from many points. Thus, there is a strong force of attraction between the metal and the ligand.

What is meant by stability of complex?

The stability of a complex in solution refers to the degree of association between the two species involved in the state of equilibrium. The magnitude of the (stability or formation) equilibrium constant for the association, quantitatively express the stability. The complex formation is a Lewis acid-base concept. K = M.

What do you mean by stability of a complex ion?

The stability of a complex in solution means the degree of association between the metal ion and the ligands involved in the state of equilibrium.

What determines the stability of molecules?

The stability of atoms depends on whether or not their outer-most shell is filled with electrons. If the outer shell is filled, the atom is stable. Atoms with unfilled outer shells are unstable, and will usually form chemical bonds with other atoms to achieve stability.

Are smaller molecules more stable?

No, it’s actually the other way around, the larger the value of the bond order, the more stable the bond. Bond order is calculated by using the number of electrons that reside in bonding orbitals and in antibonding orbitals.

Which compound is more stable?

Therefore, Ph3C+ is most stable due to presence of three benzene rings which are resonance stabilised.