Search found 52 matches

by Brandi 2C
Thu Mar 12, 2020 11:09 pm
Forum: Administrative Questions and Class Announcements
Topic: How long do we have to complete the final?
Replies: 1
Views: 56

How long do we have to complete the final?

I am a bit confused on the wording of Lavelle's last update -- He said that the exam will be about 6 questions (about 3-4 hours) but also said that time will not be an issue. Does this mean that it will be only available for 3-4 hours or that there will be a window of time in which we can complete i...
by Brandi 2C
Thu Mar 12, 2020 11:06 pm
Forum: Administrative Questions and Class Announcements
Topic: Final
Replies: 2
Views: 39

Re: Final

He just sent out an email saying that the final will be during the regular hours of the initial exam and that it will be administered online. He also said that no other software would need to be downloaded to take it, so I'm assuming it will be on CCLE to be multiple choice (unlikely) or like a fill...
by Brandi 2C
Thu Mar 12, 2020 2:13 pm
Forum: Administrative Questions and Class Announcements
Topic: Take Home Final
Replies: 16
Views: 245

Re: Take Home Final

For my math class final that is now take home, he said he will be doing a final through Gradescope wherr you submit scans of your paper work for the final and gave us a 24 hour window to do it. I hope Lavelle does the same
by Brandi 2C
Thu Mar 12, 2020 2:11 pm
Forum: Administrative Questions and Class Announcements
Topic: Format because I posted in 14A by accident
Replies: 8
Views: 106

Re: Format because I posted in 14A by accident

I assume it would be like the previous Tests and probably like the practice final he will be uploading onto the website.
by Brandi 2C
Thu Mar 12, 2020 2:10 pm
Forum: First Order Reactions
Topic: equation derivations
Replies: 9
Views: 65

Re: equation derivations

My TA told us that we should memorize the derivation for van't Hoff equation... He strongly suggested us to, so I am still not sure why would need to but I would follow his recommendation
by Brandi 2C
Thu Mar 12, 2020 2:06 pm
Forum: Student Social/Study Group
Topic: Final Exam
Replies: 22
Views: 477

Re: Final Exam

Does anyone know when we will be given our take-home final? Is it still going to be on Sunday? I think it's still going to be sunday, as there's nothing to indicate otherwise Do you know this for sure? My other professors that have take home finals still warned us that there would be a take home fi...
by Brandi 2C
Wed Mar 11, 2020 8:36 pm
Forum: Administrative Questions and Class Announcements
Topic: "Open Book" Final?
Replies: 30
Views: 651

Re: "Open Book" Final?

I believe for "open book" it does entail classroom notes, office hour notes, discussion notes and packets, and everything in between.
by Brandi 2C
Wed Mar 11, 2020 8:32 pm
Forum: Administrative Questions and Class Announcements
Topic: final
Replies: 14
Views: 179

Re: final

** It's not on Sunday anymore. **

He said it was cancelled in the email!
by Brandi 2C
Tue Mar 10, 2020 11:53 pm
Forum: Administrative Questions and Class Announcements
Topic: What is the plan for the final?
Replies: 16
Views: 228

Re: What is the plan for the final?

chari_maya 3B wrote:Does that mean the midterm is going to be wayyyyyy more influential to our grade than it would have been?


Hopefully not.....!!! I'm crossing my fingers that it will stay the same since I'm (and most likely many others) hoping that my final will make up for my midterm score!
by Brandi 2C
Tue Mar 10, 2020 11:50 pm
Forum: Student Social/Study Group
Topic: Final Exam
Replies: 22
Views: 477

Re: Final Exam

Update: The exam on Sunday is cancelled and it will be a take home :) check emails!
by Brandi 2C
Tue Mar 10, 2020 8:52 pm
Forum: Administrative Questions and Class Announcements
Topic: Reviews and Final
Replies: 1
Views: 51

Re: Reviews and Final

Hopefully the lecture will be Bruincasted since it will be a review session and also the CS50 room is compatible with Bruincast! However in my experience with asking professors about getting their classes enrolled in Bruincast, it is usually a long process (or so they say) that they need to go throu...
by Brandi 2C
Tue Mar 10, 2020 8:48 pm
Forum: Student Social/Study Group
Topic: Curve?
Replies: 31
Views: 1206

Re: Curve?

Does that line in the syllabus also mean that anyone who receives over 50% of the points will pass? Yes,,, I had a conversation with Lavelle in his office hours about this and he said that as long as you get a 50%, no matter what or how, you will PASS the class! I think we can agree this is at leas...
by Brandi 2C
Tue Mar 10, 2020 8:46 pm
Forum: Administrative Questions and Class Announcements
Topic: Office Hours/Review Sessions
Replies: 1
Views: 31

Re: Office Hours/Review Sessions

I posted this response in another thread but I think it is still relevant and helpful: "I think it would be best to keep checking Lyndon's ENDGAME Review Session thread to be kept updated on the status of his review session! But for Lavelle's review sessions, since classes have been deemed canc...
by Brandi 2C
Tue Mar 10, 2020 8:44 pm
Forum: Student Social/Study Group
Topic: Final Exam
Replies: 22
Views: 477

Re: Final Exam

Are the review sessions still going on? I think it would be best to keep checking Lyndon's ENDGAME Review Session thread to be kept updated on the status of his review session! But for Lavelle's review sessions, since classes have been deemed cancelled by Gene Block, I think we would just have to w...
by Brandi 2C
Tue Mar 10, 2020 8:41 pm
Forum: Phase Changes & Related Calculations
Topic: Fusion = Melting?
Replies: 7
Views: 127

Re: Fusion = Melting?

I believe fusion is actually a phase change between liquid and solid, which could mean either melting or freezing because those are both phase changes between liquids and solids (melting= solid -> liquid; freezing= liquid -> solid)
by Brandi 2C
Tue Mar 10, 2020 8:38 pm
Forum: Administrative Questions and Class Announcements
Topic: Class Cancellation
Replies: 3
Views: 124

Re: Class Cancellation

I'm sure that homework should still be turned in (via email with a picture or PDF file) since the discussions that happened today (like mine) still had to turn it in!
by Brandi 2C
Tue Mar 10, 2020 8:36 pm
Forum: Biological Examples
Topic: Chem Final Review Worksheet
Replies: 2
Views: 82

Re: Chem Final Review Worksheet

Lyndon (a UA) has recently posted a thread called "ENDGAME" that will have his review session packet linked in it.

Also he said he will be posting the answer key to the packet shortly after the review session (Friday 6pm)!
by Brandi 2C
Tue Mar 10, 2020 8:33 pm
Forum: Administrative Questions and Class Announcements
Topic: ENDGAME Review Session
Replies: 71
Views: 2570

Re: ENDGAME Review Session

Thank you SO MUCH for gracing us with your review sessions even though you aren't being mandated nor paid to do so!!! I think I speak for everyone when I say I love you 3000 x 3000 x 3000 x 3000!!! Also... will this review still be going on regarding the recent notification by Gene Block that classe...
by Brandi 2C
Tue Mar 10, 2020 4:19 pm
Forum: Administrative Questions and Class Announcements
Topic: ***New Coronavirus Update from UCLA***
Replies: 2
Views: 100

***New Coronavirus Update from UCLA***

https://newsroom.ucla.edu/releases/ucla-transitions-to-online-instruction?fbclid=IwAR2kgLjNSUH3uzaToY0F5mtUoGQ9ZG1B9J7krbfIB2KeTXAhX3TwRj-6hrI I am merely posting this for announcement purposes since it was circulated through links rather than through an official email. However it is from the UCLA w...
by Brandi 2C
Mon Mar 09, 2020 11:21 pm
Forum: Zero Order Reactions
Topic: Graphs
Replies: 13
Views: 419

Re: Graphs

Does this still apply to winter 20!? Re: We won't be required to draw graphs but be able to interpret them. I don't think we would be, since none of the homework problems I've looked over have a drawing aspect in them. However I think it would be wise to understand what zeroth/first/second order gr...
by Brandi 2C
Mon Mar 09, 2020 11:18 pm
Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
Topic: 6N.15
Replies: 2
Views: 30

Re: 6N.15

I think that you are supposed to use [ Ecell = Ecell* - (RT/nrF) ln K ] for this problem because the related example in section 6N used this. It's on page 565 in the textbook if you need further clarification!
by Brandi 2C
Mon Mar 09, 2020 11:15 pm
Forum: General Rate Laws
Topic: Rounding "a"
Replies: 1
Views: 22

Re: Rounding "a"

Yes -- I'm pretty sure we do since the reaction rates are usually in terms of the coefficients of the reactants/products in the reaction, which are basically always in whole number terms. I also think it should be in whole numbers for the sake of simplicity for test calculations!
by Brandi 2C
Mon Mar 09, 2020 11:12 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Tips for Test
Replies: 23
Views: 236

Re: Tips for Test

The homework problems at the end of every focus section are the most helpful because they combine lots of topics into 1 problem like the test. (i.e. 4.21, 4.43, 6.43) Would you recommend the ones in sections 5 and 6? Just for clarification which sections were the most helpful related to the Test 2?...
by Brandi 2C
Mon Mar 09, 2020 11:08 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: exothermic reaction
Replies: 4
Views: 68

Re: exothermic reaction

Since the delta H is negative, the reaction is therefore exothermic, which means that there is a release of energy in the reaction process. This wouldn't necessarily mean that energy is 'added' but actually released as a product! (through the formation of bonds in reactants A and B to create C)
by Brandi 2C
Mon Mar 09, 2020 11:05 pm
Forum: General Rate Laws
Topic: Homework 7A.1
Replies: 4
Views: 62

Homework 7A.1

Hii I was wondering if I could get some help with parts (b) and (c) for this homework question? Complete the following statements relating to the production of ammonia by the Haber process, for which the overall reaction is N2(g) + 3 H2(g) --> 2 NH3(g). (a) The rate of consumption of N2 is _________...
by Brandi 2C
Sat Mar 07, 2020 12:31 am
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Determining the cathode/anode
Replies: 9
Views: 121

Re: Determining the cathode/anode

You can use the equation Ecell = Eright - Eleft to deduce the cathode and anode. Eright would be the cathode and Eleft would be the anode.
by Brandi 2C
Sat Mar 07, 2020 12:28 am
Forum: Balancing Redox Reactions
Topic: Half rxns
Replies: 27
Views: 346

Re: Half rxns

I do know that H+ is added in acidic reactions and OH- is added in basic, but I was wondering in which situations H3O+ would be used?
by Brandi 2C
Sat Mar 07, 2020 12:26 am
Forum: Thermodynamic Systems (Open, Closed, Isolated)
Topic: Kelvin or Celsius?
Replies: 47
Views: 864

Re: Kelvin or Celsius?

Since the STP (standard temperature and pressure) and R constant are in units of Kelvin, you should be using Kelvin for your calculations. If the problem does ask for the answer in units of Celsius, just do the calculations in Kelvin and then convert to Celsius after completing the calculations so y...
by Brandi 2C
Mon Mar 02, 2020 7:17 pm
Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
Topic: delta G equations
Replies: 3
Views: 54

Re: delta G equations

My TA also said it would be important to memorize the van't Hoff equation and its derivation from the delta G standard equations of deltaG=-RTlnK. He said it was because the van't Hoff equation isn't on the formula sheet but it is highly likely to be needed on the test...
by Brandi 2C
Mon Mar 02, 2020 7:14 pm
Forum: Balancing Redox Reactions
Topic: Acidic vs. Basic Solutions
Replies: 8
Views: 81

Re: Acidic vs. Basic Solutions

Hey, I understand that you add H2O to both basic/acidic solutions and add OH-/H+ to balance the H's for them respectively, but how do you know whether a question is in a basic or acidic solution if it is not mentioned in the question description?
Thanks!
by Brandi 2C
Mon Mar 02, 2020 6:15 pm
Forum: Gibbs Free Energy Concepts and Calculations
Topic: Homework 5.55
Replies: 1
Views: 32

Homework 5.55

A reaction used in the production of gaseous fuels from coal, which is mainly carbon, is C(s) 1 H2O(g) ∆CO(g) 1 H2(g). (a) Evaluate K At 900 K, given that the standard Gibbs free energies of formation of CO(g) and H2O(g) at 900 K are 2191.28 kJ?mol21 and 2198.08 kJ?mol21, respectively. (b) A sample ...
by Brandi 2C
Mon Mar 02, 2020 11:53 am
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Tips for Test
Replies: 23
Views: 236

Re: Tips for Test

DesireBrown1J wrote:The homework problems at the end of every focus section are the most helpful because they combine lots of topics into 1 problem like the test. (i.e. 4.21, 4.43, 6.43)


Would you recommend the ones in sections 5 and 6? Just for clarification which sections were the most helpful related to the Test 2?
by Brandi 2C
Mon Mar 02, 2020 11:48 am
Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
Topic: Ways to calculate Gibbs free energy
Replies: 5
Views: 64

Re: Ways to calculate Gibbs free energy

I think it mostly just depends on what they give you. If you're given a table with delta G of different molecules, then you use the second one. I understand this, but for one of the homework questions (5J 15), we were supposed to use different methods of finding deltaG at different temperatures (25...
by Brandi 2C
Tue Feb 25, 2020 9:20 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: 6N.1
Replies: 1
Views: 28

Re: 6N.1

I'm pretty sure you are right since it would only take 1 electron to change In^3+ to In^2+.
by Brandi 2C
Tue Feb 25, 2020 9:19 pm
Forum: Balancing Redox Reactions
Topic: reducing agent
Replies: 5
Views: 46

Re: reducing agent

The reducing agent is the compound that is doing the reducing, in other words it is the one being oxidized/ in the oxidation half reaction. The opposite is said of the oxidizing agent, that it is the one doing the oxidizing, aka the one in the reduction half reaction. For me, the OIL RIG method help...
by Brandi 2C
Tue Feb 25, 2020 9:16 pm
Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
Topic: Today in lecture, Dr. Lavelle
Replies: 4
Views: 58

Re: Today in lecture, Dr. Lavelle

Did he play this in all the lectures? I don't recall this playing on Monday, and I wish I did haha
by Brandi 2C
Tue Feb 25, 2020 9:15 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Cell Diagrams
Replies: 3
Views: 50

Re: Cell Diagrams

In discussion today my TA told me that it should be the solid form of the anode/cathode that is on the inner parts of the cell diagram. But he also did an example with Platinum and said that was the best conductor
by Brandi 2C
Tue Feb 25, 2020 9:13 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: 6L.7
Replies: 1
Views: 41

Re: 6L.7

Yes, I believe you're correct. The reduction potentials can be found in the appendix of the textbook. And I'm not sure about the question you have about balancing in an acidic/basic condition. I think I remember in the book that it mentioned that you should balance in acidic conditions unless otherw...
by Brandi 2C
Tue Feb 11, 2020 6:57 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: 7th edition 6A.23
Replies: 1
Views: 25

7th edition 6A.23

Calculate the molar concentration of Ba(OH)2(aq) and the molar concentrations of Ba2+, OH2, and H3O+ in an aqueous solution that contains 0.43 g of Ba(OH)2 in 0.100 L of solution. I was wondering if someone could let me know how I can find the concentration of Ba2? I know that you can find [OH-] by ...
by Brandi 2C
Tue Feb 11, 2020 5:31 pm
Forum: Concepts & Calculations Using Second Law of Thermodynamics
Topic: Pizza Rolls 3b
Replies: 1
Views: 43

Re: Pizza Rolls 3b

The formula is q= mc delta T + 1/2 m delta Hfus

The 1/2 is due to the fact that half of it melts.
by Brandi 2C
Sat Feb 08, 2020 12:04 am
Forum: Concepts & Calculations Using Second Law of Thermodynamics
Topic: Spontaneous vs Nonspontaneous
Replies: 4
Views: 38

Re: Spontaneous vs Nonspontaneous

One thing I remember from lecture is that systems tend to go from degree of least entropy to a degree of more entropy, and that it is unnatural for a system to go to a state with less entropy. This comes from the concept with the glass flask and having the gas be secured off to one half the glass (l...
by Brandi 2C
Fri Feb 07, 2020 11:58 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: 5H.2 Clarifications
Replies: 3
Views: 38

Re: 5H.2 Clarifications

They simply added the 1st and 2nd equations together and kept the molecules on their respective sides. 2 P(g) + 3 Cl2(g) <—-> 2 PCl3(g) + 2 PCl3(g) + 2 Cl2(g) <—-> 2 PCl5(g) = 2 P + 3 Cl2 + 2 PCl3 + 2 Cl2 <-> 2 PCl3 + 2 PCl5 and you could subtract 2 PCl3 from each side and therefore removing them, ...
by Brandi 2C
Fri Feb 07, 2020 11:56 pm
Forum: Ideal Gases
Topic: Temperature
Replies: 17
Views: 138

Re: Temperature

As many students started above, K is usually your best bet. The reason for this, however, is that K is an SI unit and therefore is usually used in multiple occasions/circumstances unless it is specifically stated that the answer should be in C or even F. My old high school chemistry teacher ingraine...
by Brandi 2C
Fri Feb 07, 2020 11:53 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: 5H.2 Clarifications
Replies: 3
Views: 38

Re: 5H.2 Clarifications

They simply added the 1st and 2nd equations together and kept the molecules on their respective sides. 2 P(g) + 3 Cl2(g) <—-> 2 PCl3(g) + 2 PCl3(g) + 2 Cl2(g) <—-> 2 PCl5(g) = 2 P + 3 Cl2 + 2 PCl3 + 2 Cl2 <-> 2 PCl3 + 2 PCl5 and you could subtract 2 PCl3 from each side and therefore removing them, a...
by Brandi 2C
Tue Feb 04, 2020 4:33 pm
Forum: Administrative Questions and Class Announcements
Topic: Step Up Sessions
Replies: 15
Views: 3166

Re: Step Up Sessions

Will the current week's step up sessions be posted on here as well?

I would also like an insight to how the step up sessions are structured and how helpful they are like the posted reply above mine.
by Brandi 2C
Tue Feb 04, 2020 4:32 pm
Forum: Administrative Questions and Class Announcements
Topic: Test 1 Distribution
Replies: 9
Views: 131

Test 1 Distribution

Will we get a distribution curve for the Test 1 results? I just got my test back from my TA today in Discussion but I would like to know my score in comparison to other students to know where I stand and where I should be focusing my efforts on.
by Brandi 2C
Mon Jan 27, 2020 10:52 pm
Forum: Concepts & Calculations Using Second Law of Thermodynamics
Topic: 9.27
Replies: 3
Views: 439

Re: 9.27

Can someone please explain why HBr has a higher molar entropy than HF because I thought that you should also take into account the amount of elements available to align in such directions. I.e. HBr and HF both have 2 different elements so they can only really be aligned in similar types of directions
by Brandi 2C
Fri Jan 24, 2020 10:27 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Reaction Enthalpies calculation
Replies: 2
Views: 20

Re: Reaction Enthalpies calculation

I believe the 3rd method is the most accurate because it includes the calculations regarding phase changes, followed by the 1st, and the 2nd as the least accurate.
by Brandi 2C
Fri Jan 24, 2020 10:25 pm
Forum: Phase Changes & Related Calculations
Topic: Heat, energy, and work
Replies: 2
Views: 23

Re: Heat, energy, and work

Heat and energy are similar I believe because when you break bonds, you release energy, and when you form them you use energy. And work is a form of energy from what I remember in physics 5 series
by Brandi 2C
Fri Jan 24, 2020 10:21 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: When to use Standard enthalpies of formation
Replies: 3
Views: 47

Re: When to use Standard enthalpies of formation

I don't think you can do this for problems that are not set in standard condition because the equation for the method requires delta H ° and that only applies to bonds in standard condition.
by Brandi 2C
Fri Jan 24, 2020 10:18 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Using different methods
Replies: 4
Views: 37

Re: Using different methods

I believe you would use the second method if he's posed the question in a way that shows the Lewis structures. That's how he presented an example question in class today
by Brandi 2C
Fri Jan 24, 2020 10:16 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Calculation methods
Replies: 6
Views: 47

Re: Calculation methods

Dr. Lavelle also stressed that the second method (using bond enthalpy) was the least accurate. I don't know if that was important but I thought it was worth noting since he said it a couple times in lecture.

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