CHEMISTRY COMMUNITY

Joyce Wu 3E

Dear Dr. Lavelle, Thank you for the two most amazing education quarters of chemistry. I have never seen a more dedicated professor/ educator to his subject and his students. With countless resources, office hours, and bruincasts, you made sure that every student had the opportunity to succeed in you...

Joyce Wu 3E

The standard Gibbs energy difference between the transition state of a reaction and the ground state of the reactants. Because it usually takes energy for the reaction to happen (energy will be used to break the molecular bonds of the reactants), the gibbs free engery of activation will be positive....

Joyce Wu 3E

I'd tell you a good chemistry joke, but all the good ones [Ar]gon

Joyce Wu 3E

Yes that is correct. If B had 2 mols, then the unique rate would be multiplied by 2 for the rate of B

Joyce Wu 3E

Whether or not the reaction is reversed is based off of the overall equation that is given in the problem. It was ATP+H2O --> ADP + (HPO4)2- Seeing the 2 reactions given, we see that we needed the fructose molecules to cancel out while having the products and reactants from the given equation stay i...

Joyce Wu 3E

Usually when Gas goes to a Liquid, deltaH is a negative. Forming bonds releases energy. In contrast, when Liquid goes to a Gas, deltaH is a positive since it requires energy to break the intermolecular bonds.

Joyce Wu 3E

In a galvanic cell, the standard potential E is positive to indicate that the oxidation-reduction reaction is a spontaneous reaction for reduction at the cathode and oxidation at the anode. If it is negative, then it would not be an effective "battery" since it does not spontaneously produ...

Joyce Wu 3E

It is not as black and white as that. An endothermic reaction can be spontaneous (favorable) as well. For example, Gibbs free energy is determined by enthalpy, temperature, and entropy (delta(G) = delta(H) - T(Delta(S)). So when delta(H) is positive it means its endothermic. In this case, if delta(S...

Joyce Wu 3E

Molar heat capacity is the heat required to raise the temperature of 1 mol of a substance by 1 degree C. The reason why NO2 has higher molar heat capacity is because it has more molecular complexity than NO. Due to this, it would take more heat to raise the temp of 1 mol for NO2

Joyce Wu 3E

I saw my friends inhaling helium and I was like:
He, He, He

Joyce Wu 3E

We mostly use the H-H equation regarding buffers. This is because this equation involves a weak acid/base and its conjugate through a salt with the same anion (or cation).

Joyce Wu 3E

We plug in 1.58x10^-3 because that is the molarity (mols/Liter) of CO2. The problem says that at equilibrium, there are 0.0174 grams of CO2. Convert that to mols, it is 3.95x10^-4 mols. We are told that this is within 0.250 liters; thus, the molarity of CO2 would be (3.95x10^-4 mol)/(.250 L) = 1.58x...

Joyce Wu 3E

He actually posted the link to all the details about the final on his website :) Chem 14A Final Exam 3-6pm, Sunday, December 4. 14A-1, 11am class: Last name A-L in CS50. Last name M-Z in LAKRETZ 110. 14A-3, 1pm class: Last name A-L in CS24. Last name M-Z in CS76. 14A-4, 3pm class: Everyone in MOORE ...

Joyce Wu 3E

Yes, you are supposed to count en as 2 bonds because it is BIDENTATE which means it can bond at 2 sites (Specifically at the 2 nitrogens).

Joyce Wu 3E

How many moles are in a guacamole??
- Avacado's number

Joyce Wu 3E

So looking at the answer key (with the lewis structures) from the first Carbon from the left to right, it should be sp2, sp, sp2, sp, sp, sp3

Joyce Wu 3E

If the question requires you to draw the resonance, it will probably always ask you specifically to. Otherwise, the question would state: "draw the most STABLE lewis structure". Which simply means the one with the lowest formal charge.

Joyce Wu 3E

Electronegativity can be defined as "the power of an atom in a molecule to attract electrons to itself". In a non-polar covalent bond, there is an equal sharing of electrons in the bond; thus, the electronegativity difference is very small. In a polar covalent bond, there is an unequal sha...

Joyce Wu 3E

But seriously we need to combat global warming and help the polar bears

Joyce Wu 3E

Oxygen and Magnesium are going out, like OMg!!

Joyce Wu 3E

I took AP chemistry back when I was a sophomore in high school and am now taking 14A as a freshman in college so I understand how frustrating it is to forget the majority of the chemistry once learned. One tip I would have is to finish all the modules Dr. Lavelle posted on his website and also breez...

CHEMISTRY COMMUNITY

Search found 21 matches

Re: Saying Thank You to Dr. Lavelle

Re: Standard Gibbs Free Energy of Activation

Re: Post All Chemistry Jokes Here

Re: Unique Average Rate Question

Re: Winter Midterm 2016: Q5A

Re: Phase changes

Re: Standard Potential E [ENDORSED]

Re: favorability

Re: 8.29 in Textbook [ENDORSED]

Re: Post All Chemistry Jokes Here

Re: When to use H-H equation

Re: Homework 11.41

Re: About Final

Re: #4 in Quiz Prep 3 2015 [ENDORSED]

Re: Post All Chemistry Jokes Here

Re: Fall 2014 Quiz 2 Prep #4

Re: Resonance vs. Lewis Structure?

Re: Ionic vs. Covalent Bonds [ENDORSED]

Re: Post All Chemistry Jokes Here

Re: Chemistry Joke

Re: Rusty on High School Chem [ENDORSED]