Search found 30 matches

by Jimmy Zhang Dis 1K
Mon Mar 19, 2018 12:00 am
Forum: Van't Hoff Equation
Topic: Practice Test
Replies: 5
Views: 479

Re: Practice Test

We will not have to
by Jimmy Zhang Dis 1K
Mon Mar 19, 2018 12:00 am
Forum: Van't Hoff Equation
Topic: Finding K
Replies: 5
Views: 479

Re: Finding K

We do not need them
by Jimmy Zhang Dis 1K
Sun Mar 18, 2018 11:59 pm
Forum: General Rate Laws
Topic: Rate constant units
Replies: 6
Views: 374

Re: Rate constant units

In general the constant is M^1-n*time^-1
by Jimmy Zhang Dis 1K
Sun Mar 11, 2018 11:54 pm
Forum: Second Order Reactions
Topic: the slope
Replies: 12
Views: 390

Re: the slope

Image
by Jimmy Zhang Dis 1K
Sun Mar 11, 2018 11:50 pm
Forum: Zero Order Reactions
Topic: graph of 0 order
Replies: 10
Views: 354

Re: graph of 0 order

Image
by Jimmy Zhang Dis 1K
Sun Mar 11, 2018 11:49 pm
Forum: Zero Order Reactions
Topic: Half-Life of Zero Order
Replies: 3
Views: 197

Re: Half-Life of Zero Order

It would probably be good to know for the test. Even though the book mentioned it won't be used Lavelle might decide to put it in a problem
by Jimmy Zhang Dis 1K
Sun Mar 04, 2018 11:56 pm
Forum: General Rate Laws
Topic: graphs
Replies: 2
Views: 88

Re: graphs

Image
by Jimmy Zhang Dis 1K
Sun Mar 04, 2018 11:52 pm
Forum: General Rate Laws
Topic: zero order in rate laws
Replies: 8
Views: 180

Re: zero order in rate laws

No, the zero order reaction has no effect on the rate law so normally its not included.
by Jimmy Zhang Dis 1K
Sun Mar 04, 2018 11:50 pm
Forum: General Rate Laws
Topic: Negative Order 15.3
Replies: 2
Views: 86

Re: Negative Order 15.3

Also for a negative order reaction the overall order is normally undefined (like 2nd order + -1 order has a more complex rate constant than just first order)
by Jimmy Zhang Dis 1K
Sun Feb 25, 2018 11:50 pm
Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
Topic: Nernst Equation
Replies: 6
Views: 199

Re: Nernst Equation

It is the total amount of electrons transferred. This can be found by combining two half reactions for the redox reactions.
by Jimmy Zhang Dis 1K
Sun Feb 25, 2018 11:37 pm
Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
Topic: calculating n
Replies: 9
Views: 328

Re: calculating n

To calculate n you would need to find the number of electrons transferred in each half reaction. If they match up, that is your n value. If they don't the lowest multiple of the two is you n value.
by Jimmy Zhang Dis 1K
Sun Feb 25, 2018 11:34 pm
Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
Topic: standard conditions [ENDORSED]
Replies: 4
Views: 118

Re: standard conditions [ENDORSED]

I believe standard conditions just represents things like 298K and 1atm. It doesn't necessarily mean the system is at equilibrium
by Jimmy Zhang Dis 1K
Sun Feb 18, 2018 11:49 pm
Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
Topic: Nernst Equation (log vs. ln)
Replies: 5
Views: 317

Re: Nernst Equation (log vs. ln)

During discussion my TA mentioned that there is no difference, but if you use ln it is easier to relate to other equations that also use ln
by Jimmy Zhang Dis 1K
Sun Feb 18, 2018 11:45 pm
Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
Topic: E vs E naught
Replies: 3
Views: 145

E vs E naught

Can someone explain the difference between E and E naught? Is it the same as G vs G naught?
by Jimmy Zhang Dis 1K
Sun Feb 18, 2018 11:43 pm
Forum: Administrative Questions and Class Announcements
Topic: Quiz 2
Replies: 1
Views: 108

Quiz 2

Should we expect the same format for Quiz 2 as Quiz 1? Some multiple choice and mostly free response?
by Jimmy Zhang Dis 1K
Fri Feb 09, 2018 11:21 am
Forum: Administrative Questions and Class Announcements
Topic: Lecture Slides
Replies: 6
Views: 233

Lecture Slides

I know that Lavelle has lecture outlines but does he post the actual slides anywhere?
by Jimmy Zhang Dis 1K
Fri Feb 09, 2018 10:48 am
Forum: Administrative Questions and Class Announcements
Topic: Bruin Cast
Replies: 5
Views: 216

Re: Bruin Cast

Its not but he does post lecture outlines like this:
https://lavelle.chem.ucla.edu/wp-conten ... rochem.pdf

to help when you are reading through the textbook
by Jimmy Zhang Dis 1K
Fri Feb 09, 2018 10:36 am
Forum: Administrative Questions and Class Announcements
Topic: Midterm Review Sessions
Replies: 1
Views: 108

Midterm Review Sessions

Does anyone have a link for the midterm review sessions? I can't seem to find it on the website
by Jimmy Zhang Dis 1K
Fri Feb 02, 2018 3:20 am
Forum: Gibbs Free Energy Concepts and Calculations
Topic: G=H-TS
Replies: 4
Views: 145

Re: G=H-TS

As a general guideline for deltaG:
+deltaS and -deltaH means spontaneous at all temp
+deltaS and +deltaH means spontaneous at high temp
-deltaS and-deltaH means spontaneous at low temp
-deltaS and +deltaH means not spontaneous at all
by Jimmy Zhang Dis 1K
Fri Feb 02, 2018 3:14 am
Forum: Concepts & Calculations Using First Law of Thermodynamics
Topic: bond enthalpy [ENDORSED]
Replies: 4
Views: 139

Re: bond enthalpy [ENDORSED]

I think that bond enthalpies can be considered constants that aren't affected by outside sources like polarity
by Jimmy Zhang Dis 1K
Fri Feb 02, 2018 3:02 am
Forum: Gibbs Free Energy Concepts and Calculations
Topic: Calculation methods
Replies: 3
Views: 99

Re: Calculation methods

Yes, I believe that you can use any of the methods we have previously learned to calculate delta H
by Jimmy Zhang Dis 1K
Fri Jan 26, 2018 11:02 am
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: deltaH Units
Replies: 5
Views: 175

Re: deltaH Units

I believe that standard delta H and delta H of a reaction are in KJ while delta H of formation is in KJ/mol
by Jimmy Zhang Dis 1K
Fri Jan 26, 2018 10:57 am
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: The sign of q
Replies: 5
Views: 168

Re: The sign of q

I think the system should be thought of as the calorimeter which is gaining heat and thus the q is considered positive
by Jimmy Zhang Dis 1K
Fri Jan 26, 2018 10:42 am
Forum: Phase Changes & Related Calculations
Topic: Heat and Work relation
Replies: 6
Views: 205

Re: Heat and Work relation

Normally when solving delta U = q(heat) + w(work) q and w are calculated separately. The work could have a negative or positive value depending on the delta V in the equation.
by Jimmy Zhang Dis 1K
Fri Jan 19, 2018 9:19 am
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: 8.103
Replies: 2
Views: 100

Re: 8.103

Yes, in the average kinetic energy equation R represents the ideal gas constant: 8.3145 J/K*mol
by Jimmy Zhang Dis 1K
Fri Jan 19, 2018 9:17 am
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: 8.29
Replies: 4
Views: 119

8.29

In the solution manual it says that NO2 has a higher heat capacity because of "more possible bond vibrations." Is it safe to assume that a molecule with more bonds will have a higher heat capacity?
by Jimmy Zhang Dis 1K
Fri Jan 19, 2018 9:11 am
Forum: Phase Changes & Related Calculations
Topic: HW question
Replies: 5
Views: 177

Re: HW question

Yes, you can choose any 14 questions from chapter 8. As of right now we haven't learned any other chapters.
by Jimmy Zhang Dis 1K
Thu Jan 11, 2018 10:46 pm
Forum: Phase Changes & Related Calculations
Topic: Ideal Gas
Replies: 5
Views: 188

Re: Ideal Gas

As mentioned above an ideal gas is a hypothetical version of a gas whose molecules do not repel/attract eachother and also take up no volume. This allows you to apply equations like PV=nRT to solve problems. In the real world it is unlikely that any gases follow this law.
by Jimmy Zhang Dis 1K
Thu Jan 11, 2018 10:40 pm
Forum: Phase Changes & Related Calculations
Topic: Endo and Exothermic Ways to Remember
Replies: 28
Views: 1725

Re: Endo and Exothermic Ways to Remember

I personally remember it from the acronym MEXOBENDO where the M stands for making and the B stands breaking. This gives you Making(bonds) EXOthermic and Breaking ENDOthermic
by Jimmy Zhang Dis 1K
Thu Jan 11, 2018 10:35 pm
Forum: Phase Changes & Related Calculations
Topic: Superheating
Replies: 6
Views: 278

Re: Superheating

Superheating, or boiling delay occurs when a liquid is heated past its boiling point without actually boiling. This normally only occurs in homogeneous substances.

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