Search found 14 matches

Sat Mar 12, 2016 2:11 pm
Forum: *Cycloalkenes
Topic: Q7A. 2011 Winter Final
Replies: 3
Views: 493

Re: Q7A. 2011 Winter Final

Do we not need to indicate where the double bond is?
Sat Mar 12, 2016 1:42 am
Forum: General Rate Laws
Topic: 2011 Final, Question 4A
Replies: 3
Views: 628

Re: 2011 Final, Question 4A

You are not integrating by first order. You are just integrating each side, keeping the nth order in the equation. It's just a calculous problem. You also know that rate=k*(concentration of reactant)^order#. Since A is your only reactant, and the problem says to find the rate in the nth order, you c...
Wed Feb 10, 2016 1:01 am
Forum: Balancing Redox Reactions
Topic: Midterm 2014 Question 8
Replies: 4
Views: 499

Re: Midterm 2014 Question 8

In this specific question, we are looking to find Ka of HF. Since Ka has to do with the amount of HF that dissociates, we need the equation for dissociation of HF. This would be HF<-->H(+)+F(-). Normally, if looking to balance a normal redox or make a battery cell, we would want the Eo value to be p...
Tue Feb 09, 2016 8:59 pm
Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
Topic: E of a Redox [ENDORSED]
Replies: 5
Views: 646

E of a Redox[ENDORSED]

Could someone please explain why when you multiply a half reaction, the E does not change? I'm just confused why entropy and enthalpy change when the reaction is flipped or multiplied bye E does not. I know that there is a difference because S and H are thermo and E is electric, but I do not get why...
Tue Feb 09, 2016 7:49 pm
Forum: Third Law of Thermodynamics (For a Unique Ground State (W=1): S -> 0 as T -> 0) and Calculations Using Boltzmann Equation for Entropy
Topic: WInter 2013 Midterm Q5B
Replies: 1
Views: 318

WInter 2013 Midterm Q5B

This question asks us to arrange CHF5, CF4, CH3F, and CH2F2 in order of increasing molar entropy. The answer says that CH3F < CH2F2 < CHF3 < CF4. I thought that the entropy was determined mostly by W, which is the number of different states to the power of the n particles. So Why is it that when CHF...
Tue Feb 09, 2016 7:16 pm
Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
Topic: Winter 2013 Q3A
Replies: 1
Views: 335

Winter 2013 Q3A

This question asks us to calculate the work done by steam. To do this, the answer uses w=-P(delta)V and PV=nRT to derive that w=-(delta)nRT. I'm confused as to how the delta is applied to nRT, as it doesn't seem to change any of the calculations. Can someone explain to me how the delta fits into nRT?
Tue Feb 09, 2016 2:07 pm
Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
Topic: Winter 2011 Midterm Q6C
Replies: 1
Views: 313

Winter 2011 Midterm Q6C

For part C of question 6 on the 2011 winter midterm, it asks to find G for the redox reaction. Could someone explain how to find the equation G=-nFE is found? Because I know that the equation of deltaG=-nFE is given, but why can it be changed from the change in gibbs free energy to the total gibbs f...
Sat Feb 06, 2016 11:24 pm
Forum: Administrative Questions and Class Announcements
Topic: Quiz 1
Replies: 1
Views: 325

Re: Quiz 1

My TA for section 1C said our average was a 25/40, but I believe it varied by section
Sat Jan 23, 2016 7:54 pm
Forum: Concepts & Calculations Using First Law of Thermodynamics
Topic: Calculations
Replies: 1
Views: 261

Re: Calculations

Honestly, the best way to find equations is to look at what you are given and what you need to find. Then, you should look on the equation sheet and pick out the equations that have these variables in them. If you do not know enough of the variables, typically you will need to use your givens in ano...
Fri Jan 15, 2016 10:22 pm
Forum: Student Social/Study Group
Topic: Post All Chemistry Jokes Here
Replies: 8252
Views: 1445233

Re: Chemistry Jokes

Throwback to 14A :)
Fri Jan 15, 2016 10:10 pm
Forum: Phase Changes & Related Calculations
Topic: Steam Burns
Replies: 4
Views: 808

Re: Steam Burns

If you look at the graph, blue represents solid, green represents liquid, and red represents gas. It is apparent when studying this graph that the gas form contains more energy than the liquid form, even at the same temperature. Because of this, there is more energy to be released by steam when it c...
Sat Dec 05, 2015 2:29 pm
Forum: Photoelectric Effect
Topic: VIDEO: Fall Midterm 2014 (3&4)
Replies: 1
Views: 437

VIDEO: Fall Midterm 2014 (3&4)

Lily Kennedy and Lydia Elson video, lecture 3.
Wed Oct 14, 2015 10:12 pm
Forum: Electronegativity
Topic: Does a greater difference in EN correlate to a stronger bond
Replies: 2
Views: 1071

Re: Does a greater difference in EN correlate to a stronger

Generally, yes. A bigger difference in electronegativity indicates that the bond is more ionic. Since ionic bonds are known to have strong bonding characteristics, it makes sense that the more ionic a bond is, the stronger the bond.
Sun Oct 04, 2015 3:40 pm
Forum: Significant Figures
Topic: How many sf to carry through in problems with multiple parts
Replies: 5
Views: 926

Re: How many sf to carry through in problems with multiple p

My AP teacher taught that we should use the correct sig figs to answer part A, but use the full answer in further calculations (keeping in mind the final answer cannot have more than the two sig figs in the first answer). Is that correct, or would that mess up the final answer?