CHEMISTRY COMMUNITY

Veritas Kim 2L

How do we determine the molecularity given the rate laws? You can look at the number of reactants in the chemical equation to determine the molecularity of the rate laws. If there is only one reactant=unimolecular two reactants=bimolecular three reactants=termolecular (highly unlikely in real life ...

Veritas Kim 2L

Yes. Dr. Lavelle said that it would be way too much work to use the steady-state and so we wouldn't be using this method for this class.
Just focus on the pre-equilibrium condition!

Veritas Kim 2L

Could someone explain in detail 15.85b?
#85b what does it mean that the role of the Ar is to remove energy as the product forms?
Ar doesn't appear in the chemical equation but we still have to count it in the overall molecularity?

Veritas Kim 2L

Yes, intermediates will always appear as the products first and then used up as a reactant in the following step. However, catalysts will always appear on the reactant side first. Catalysts are not consumed!

Veritas Kim 2L

I understand that we need to know the overall relationship between reactions, temperature, kinetic energy, and activation energy in the collision theory. Do we also need to know the collision frequency, mean relative speed equations, and steric factors as well?

Veritas Kim 2L

When we use the integrated first order rate law for this particular problem, why is it not necessary to convert the mass given to concentrations in molarity? It says that the "knowledge of the volume is not required" in the solutions manual.

Veritas Kim 2L

Can someone explain how to get the order of [B]?
I got exact numbers for [A] and [C] but I keep getting decimal points for [B].

Veritas Kim 2L

How do we know when and when not to use more than one species' concentration?

Veritas Kim 2L

What is pseudo-first order reaction and how is that related to the second-order reaction?

Veritas Kim 2L

what is the significance of the overall order?

Veritas Kim 2L

No, I think as long as you have a balance equation with all the H+, e-, and H20 on the right side (reactant or product) with the arrow pointing in the right direction (reduction/oxidation) you will be fine.

Veritas Kim 2L

Does the order matter when we are writing the half reactions as long as we are able to cancel the number of electrons correctly?
If we are writing an oxidation half reaction, does it have to be Zn+ arrow Zn2+ + e-? or can we write it as Zn2+ + e- arrow Zn+ ?

Veritas Kim 2L

For the anode reaction, O2 being oxidized to H+, do we ignore the H+ and balance it with 2H2O or do we balance the reaction by adding H+ on the O2 side?

Veritas Kim 2L

So balancing the number of H with H+ or H3O+ is both considered correct? If I balance H with H30+ I have to go back and balance the other side's number of O again...

Veritas Kim 2L

Our textbook and the Redox Instruction on the web posted by Dr. Lavelle tells us to just add H+ to balance the number of H on the other side, but our TA said it would be wrong to do so. The correct way to balance H is to add H30+ so which way are we supposed to balance the H? H30+ is making it confu...

Veritas Kim 2L

Equilibrium constant is unchanged when concentrations or pressure change, but it changes with temperature. Why is that?

Veritas Kim 2L

Entropy is the amount of disorder in the universe and the more complex and higher the mass (heavier), it is going to create much more vibrational energy which adds more disorder.

Veritas Kim 2L

What is the difference between Gibbs free energy of reaction and Standard Gibbs free energy of reaction?

Veritas Kim 2L

How do we know that it is 4^N and not 4^4?

Veritas Kim 2L

Could someone explain what exactly the residual entropy means?

Veritas Kim 2L

Do we have to indicate the signs of entropy?

Veritas Kim 2L

How can spontaneous change not even occur at all? (from section 9.1)

Veritas Kim 2L

You can always assume that delta S(system)= -delta S(surrounding) for a reversible expansion at equilibrium because the heat that flows to the surrounding is being released by the system.

Veritas Kim 2L

I think that is the definition of a reversible deltaStot. For a it to be considered a reversible reaction, entropy of the system must be exactly the opposite of the surrounding and vice versa.

Veritas Kim 2L

If you look at the outline for chapter 8, it says that born-haber is not included!

Veritas Kim 2L

A system was heated by using 300.J of heat, yet it was found that its internal energy decreased by 150. J Calculate w. Was work done on the system, or did the system do work?
How do you tell that 300. J is a negative? Is it because it produced heat?

Veritas Kim 2L

Which substances might show characteristics of superheating and supercooling? If one substance were to have superheating characteristics, does that mean it will also have supercooling as well? Or are the characteristics independent of each other?

Veritas Kim 2L

Yes. I think that in order to maintain reversible process during gas expansion, the external pressure has to match the pressure of the gas at every stage of the expansion and reach the maximum work since even an infinitely small change makes it reversible.

Veritas Kim 2L

Just as the others above have mentioned, "per degree Celsius" and "per Kelvin" are the same since it is just dealing with delta T (change in temperature). So you wouldn't necessarily have to convert Celsius to Kelvin by adding 273.15. You can also note that it is the same when ca...

Veritas Kim 2L

If reversible process is one that is reversed by an infinitely small change, how come an expansion against an external pressure that differs by finite amount from the pressure of the system be an irreversible one?

CHEMISTRY COMMUNITY

Search found 30 matches

Re: Question 15.85

Re: Steady-State Approximation vs. Pre-equilibrium Condition

HW #15.85 b

Re: Identifying a catalyst in a reaction

Final-Collision Theory

HW #15.37c

HW 15.19a

Using more than one species [ENDORSED]

Pseudo-First Order Reaction [ENDORSED]

Overall order

Re: Does order matter?

Half Reaction Order

14.11d

Re: Balancing H+

Balancing H+

Section 11.11

Re: Vibrational Energy State

Re: Gibbs free

Example 9.8

Residual Entropy

Re: entropy sign

Spontaneous Change

Re: delta S(system) vs delta S(surroundings)

Re: entropy

Re: Week 3 Test Topic is endorsed

Self-Test 8.5B

Heating Curves

Re: 8.3 Reversible Isothermal Expansion

Re: Celsius the same as Kelvin? [ENDORSED]

Irreversible vs Reversible