Search found 35 matches

by Skolli20
Sat Mar 18, 2017 3:58 am
Forum: Gibbs Free Energy Concepts and Calculations
Topic: Difference between G(naught) and change in G
Replies: 2
Views: 937

Re: Difference between G(naught) and change in G

Delta G nought is just delta G at standard conditions. Delta G is just the change in free energy.
by Skolli20
Tue Mar 14, 2017 1:02 pm
Forum: *Alkanes and Substituted Alkanes (Staggered, Eclipsed, Gauche, Anti, Newman Projections)
Topic: Angle of 60/180 or 0 and 120
Replies: 3
Views: 497

Re: Angle of 60/180 or 0 and 120

That was helpful! Thanks! Could you explain how you would know where to put the bromine/chlorine etc for the example you gave? Like if they said draw a newman projection with a dihedral angle of 120, how would you know where to put them vs when you draw one with a dihedral angle of like 0,180 or eve...
by Skolli20
Tue Mar 14, 2017 12:24 am
Forum: *Alkanes and Substituted Alkanes (Staggered, Eclipsed, Gauche, Anti, Newman Projections)
Topic: Angle of 60/180 or 0 and 120
Replies: 3
Views: 497

Angle of 60/180 or 0 and 120

When a question asks you to draw a Newman projection in 0 degrees or 120 degrees, since both are eclipse you could draw the same molecule right? And the same goes for 60 degrees or 180 degrees since both are staggered. it would be the same molecule right? Like I understand if they say draw the 60 de...
by Skolli20
Sat Mar 11, 2017 9:42 pm
Forum: Administrative Questions and Class Announcements
Topic: Final Exam Details and Review Sessions Winter 2017
Replies: 114
Views: 13675

Re: Final Exam Details and Review Sessions Winter 2017

Will we need to know about phenol, esters, amides, nitriles, thiols or thioethers?

Thanks!
by Skolli20
Tue Mar 07, 2017 5:34 pm
Forum: *Free Energy of Activation vs Activation Energy
Topic: Entropy and Catalysts
Replies: 1
Views: 645

Entropy and Catalysts

I know that a catalyst reduces the free energy of activation by weakening bonds and thus lowers the standard enthalpy of activation, but how does it raise the standard entropy of activation? If entropy decreases when bonds are formed because there are now less free- floating molecules, then how does...
by Skolli20
Tue Mar 07, 2017 2:03 pm
Forum: *Nucleophiles
Topic: 4.7-4.10 in organic textbook
Replies: 1
Views: 485

4.7-4.10 in organic textbook

Hi I was just wondering why we are practicing drawing lewis structures? Is there something conceptually new other than the fact that they are nucleophiles we should understand or is it just as a review? Also for 4.8, the lewis structure for thiosulfate, I thought that there would be a double bond to...
by Skolli20
Thu Mar 02, 2017 11:41 pm
Forum: *Electrophiles
Topic: Polarized/ Polarizability in terms of nucleophiles and electrophiles
Replies: 1
Views: 557

Polarized/ Polarizability in terms of nucleophiles and electrophiles

Because much of the definitions of electrophiles and nucleophiles deals with the definitions of polarized and polarizability, I was wondering if anyone could just briefly go over how the two terms are different in respect to orgo? I looked through the 14A course reader and some chemistry community p...
by Skolli20
Mon Feb 20, 2017 4:59 pm
Forum: Administrative Questions and Class Announcements
Topic: Textbook Coverage
Replies: 1
Views: 347

Re: Textbook Coverage

I was wondering the same thing! Which problems should we know how to do by the end of page 73?
by Skolli20
Sun Feb 19, 2017 1:34 pm
Forum: General Science Questions
Topic: Sig Figs
Replies: 5
Views: 963

Re: Sig Figs

Does this mean that we only use sig figs at the end of each problem, such as say, we are given numbers in the problem with only 3 sigfigs, so do we end the problem with 3 too and disregard the addition/multiplication etc that the problem requires?
by Skolli20
Sat Feb 11, 2017 11:09 pm
Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
Topic: 14.41
Replies: 4
Views: 461

Re: 14.41

Edward can you be more explicit please or can someone please clarify? I am still confused as to why n=1
by Skolli20
Sat Feb 11, 2017 9:30 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: 14.31 [ENDORSED]
Replies: 3
Views: 507

Re: 14.31 [ENDORSED]

Just to be sure, E standard needs to be positive for the reaction to be spontaneous, correct?
by Skolli20
Fri Feb 10, 2017 10:32 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: 14.31 [ENDORSED]
Replies: 3
Views: 507

14.31 [ENDORSED]

Q: Identify the reactions with K > 1 in the following list and, for each such reaction, identify the oxidizing agent and calculate the standard cell potential. For this question, do we need to find K for each equation using the equation that related equilibrium constant and E standard? Because in th...
by Skolli20
Fri Feb 10, 2017 9:36 pm
Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
Topic: 14.27 [ENDORSED]
Replies: 2
Views: 387

14.27 [ENDORSED]

Hi so I was wondering for this question if we need to change E into G because E is not a state function? The question reads:

Using data in Appendix 2B, calculate the standard potential for the half-reaction U4 (aq)+ 4 e- ---> U(s).
by Skolli20
Fri Feb 10, 2017 8:44 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: 14.29
Replies: 2
Views: 326

14.29

For question 29 it reads Suppose that each of the following pairs of redox couples is joined to form a galvanic cell that generates a current under standard conditions. Identify the oxidizing agent and the reducing agent, write a cell diagram, and 2 calculate the standard cell potential. (a) Co /Co ...
by Skolli20
Sun Jan 29, 2017 12:16 am
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: Orientations for Degeneracy
Replies: 2
Views: 312

Orientations for Degeneracy

How do we know how many orientations a molecule can make? Is it something we just have to visually be able to tell?
by Skolli20
Fri Jan 27, 2017 12:51 am
Forum: Concepts & Calculations Using Second Law of Thermodynamics
Topic: Cv and Cp
Replies: 1
Views: 269

Cv and Cp

So in many homework problems, there are many problems that deal with Cp and Cv for an ideal gas. Should we have these numbers (such as 3/2R for Cv and 5/2R for Cp) memorized, or is there a concept here that I'm missing? Are there more that we are required to know other than the above mentioned? Than...
by Skolli20
Sun Jan 22, 2017 7:02 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: 8.93 part c
Replies: 2
Views: 281

8.93 part c

8.93 says: a) Calculate the work that must be done against the atmosphere for the expansion of the gaseous products in the combustion of 1.00 mol C6H6 (l) at 25 degrees celsius, and 1 barr. b) Using data in appendix 2A, calculate the standard enthalpy of the reaction. c) Calculate the change in inte...
by Skolli20
Sat Jan 21, 2017 2:10 pm
Forum: Thermodynamic Systems (Open, Closed, Isolated)
Topic: Degeneracy [ENDORSED]
Replies: 3
Views: 503

Re: Degeneracy [ENDORSED]

I thought O2 did have a w=0 because in the natural state oxygen is found in its diatomic state, so this it acted as an reference point. But I maybe I have this confused with something else... someone let me know?
by Skolli20
Thu Jan 12, 2017 3:42 pm
Forum: Administrative Questions and Class Announcements
Topic: UA Preferences
Replies: 4
Views: 664

Re: UA Preferences

If you live on the hill, I found Erica to be a really good UA for the Hedrick Hall sessions. She explained things really clearly and effectively! Hope this helped.
by Skolli20
Sat Dec 03, 2016 1:33 am
Forum: Administrative Questions and Class Announcements
Topic: Final Review Session Chem 14A Fall 2016
Replies: 2
Views: 2110

Re: Final Review Session Chem 14A Fall 2016

Thanks Dr. Lavelle! This was super helpful :)

Quick question: is recognizing a strong acids/bases sufficient for the final or should we have the names and the molecular compounds memorized?
by Skolli20
Sat Dec 03, 2016 12:12 am
Forum: Equilibrium Constants & Calculating Concentrations
Topic: 2012 Final #6B
Replies: 3
Views: 521

Re: 2012 Final #6B

When you do it with the ICE chart, you get 61% but it's off by the decimals... is there a reason for this? Or is doing it with an ICE chart a correct way of doing it?
by Skolli20
Thu Dec 01, 2016 2:02 pm
Forum: *Titrations & Titration Calculations
Topic: Hwk 13.29
Replies: 5
Views: 794

Re: Hwk 13.29

"dude ive been doing this problem for around an hour and i finally got it. so first you find the moles of HCl (Because it's at the stoich point, and since NaOH is impure, we're gonna use HCl to find out NaOH) 0.0695 mol HCl x 0.03420 L = 0.0023769 moles HCl so that means that there are 0.002376...
by Skolli20
Wed Nov 30, 2016 9:30 pm
Forum: *Making Buffers & Calculating Buffer pH (Henderson-Hasselbalch Equation)
Topic: 13.1
Replies: 1
Views: 298

13.1

So the question reads: Explain what happens to (a) the concentration of H3O ions in an acetic acid solution when solid sodium acetate is added; I thought that adding solid sodium acetate wouldn't affect anything because solids are not considered in Le Chatelier's principle (which is what the solutio...
by Skolli20
Wed Nov 30, 2016 9:19 pm
Forum: *Titrations & Titration Calculations
Topic: ICE
Replies: 5
Views: 505

Re: ICE

I also just want to mention what another student told me today at a review session. You can't just blindly approximate if you see the Ka or Kb value is 10^-5. Take the extra 2 minutes and make sure that it is actually 5% because if the initial value is smaller than 10^-5 it will mess up your calcula...
by Skolli20
Thu Nov 24, 2016 10:36 pm
Forum: Non-Equilibrium Conditions & The Reaction Quotient
Topic: 11.59
Replies: 1
Views: 356

11.59

Hi everyone, so while I was doing the chapter 11 homework, I came across this problem - A reaction mixture is prepared by mixing 0.100 mol SO2, 0.200 mol NO2, 0.100 mol NO, and 0.150 mol SO3 in a 5.00-L reaction vessel. The reaction SO2(g) NO2(g) ∆ NO(g) SO3(g) is allowed to reach equilibrium at 460...
by Skolli20
Fri Nov 18, 2016 3:02 am
Forum: Shape, Structure, Coordination Number, Ligands
Topic: coordination number [ENDORSED]
Replies: 3
Views: 474

Re: coordination number [ENDORSED]

So the coordination number is how many bonds there are to the central metal inside the coordination complex, which is indicated by the brackets. Hopefully this answers your question!
by Skolli20
Wed Nov 09, 2016 3:11 pm
Forum: *Molecular Orbital Theory (Bond Order, Diamagnetism, Paramagnetism)
Topic: MO theory
Replies: 3
Views: 369

Re: MO theory

Yes, I'm pretty sure that having a bond order that is fractional means that it has do something with a resonance structure. For example, Ozone would have a bond order of 1.5 meaning that it's the average of a double and a single bond.
by Skolli20
Wed Nov 09, 2016 3:08 pm
Forum: *Molecular Orbital Theory (Bond Order, Diamagnetism, Paramagnetism)
Topic: Heteronuclear Diatomic Molecules
Replies: 1
Views: 304

Re: Heteronuclear Diatomic Molecules

IN the atomic orbital part of the molecular orbital theory, you just draw it the way you would for an electron configuration, I believe! This is how I would do your example. You know that hydrogen has one valence electron right? So you put that one valence electron in the S orbital. Then, for fluori...
by Skolli20
Fri Oct 28, 2016 5:41 pm
Forum: Hybridization
Topic: Hybridization [ENDORSED]
Replies: 4
Views: 594

Re: Hybridization [ENDORSED]

The part I'm confused about is how you know that one area of electron density is sp, or that three is 2sp2 etc. If someone could please explain that?
by Skolli20
Fri Oct 21, 2016 5:22 pm
Forum: Resonance Structures
Topic: Radicals
Replies: 3
Views: 441

Re: Radicals

Brian, I thinkthat radicals are not stable and thus we don't want them to create a bond with DNA. If they do, they would mess up the molecules structure/shape.
by Skolli20
Mon Oct 17, 2016 9:55 am
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Electron Configuration for Transition metals? [ENDORSED]
Replies: 1
Views: 319

Electron Configuration for Transition metals? [ENDORSED]

I was doing some of the problems for chapter 2 and I noticed that silvers electron configuration was written differently than expected. It is [Kr] 4d^10 5s^1 but I thought it would be [Kr]4d^95s^2. Can someone please explain how to write the electron configuration for transition metals in general? T...
by Skolli20
Fri Oct 07, 2016 7:09 pm
Forum: Trends in The Periodic Table
Topic: orbitals
Replies: 2
Views: 415

Re: orbitals

Bumping for the question and to clarify what he said about orbitals in class. What did groups in the periodic table did he say were S, which were P and which were d?
by Skolli20
Fri Sep 30, 2016 8:50 pm
Forum: SI Units, Unit Conversions
Topic: Conversions [ENDORSED]
Replies: 8
Views: 1005

Re: Conversions [ENDORSED]

I dont think we need to memorize such values but I would know how to do it.
by Skolli20
Thu Sep 29, 2016 4:11 pm
Forum: SI Units, Unit Conversions
Topic: Convert eV to J [ENDORSED]
Replies: 2
Views: 622

Re: Convert eV to J [ENDORSED]

This isn't something that has to be memorized right? All these conversions will be provided for us on quizzes and exams?

Go to advanced search