Search found 33 matches

by Kim
Sun Mar 19, 2017 12:48 pm
Forum: Administrative Questions and Class Announcements
Topic: midterm vs final question
Replies: 1
Views: 315

midterm vs final question

in the winter 2014 final exam, #2 part B is based on a container with two compartments separated by a divider. when the divider is lifted, there is considered a change in volume. But in this year's midterm, 2A has the same set up (two compartments divided by a wall) but opening the valve is not cons...
by Kim
Fri Mar 17, 2017 2:21 pm
Forum: *Amines
Topic: 2.35
Replies: 2
Views: 695

2.35

this question asks you to name a certain compound the answer is N-ethyl-N-methylpropan-1-amine how does one get to that answer? How do you know where to put the N's and where to split the words to put numbers? the structure looks like: http://www.syntechem.com/getImage/?smiles=CCCN(C)CC&w=167&am...
by Kim
Thu Mar 16, 2017 2:21 pm
Forum: Phase Changes & Related Calculations
Topic: reversible process
Replies: 3
Views: 352

reversible process

what's the actual concept behind a irreversible/reversible process? I understand you use different equations for each but what does it actually mean for a reaction to be reversible? what does it have to do with pressure?
by Kim
Tue Mar 14, 2017 8:08 am
Forum: General Rate Laws
Topic: coefficients
Replies: 2
Views: 314

Re: coefficients

Coefficients are only placed in the rate law when you are given the rate limiting step in a reaction mechanism. If don't have such information, you cannot assume that the overall reaction determines the rate law. To determine the rate law in that scenario, you must calculate it using different expe...
by Kim
Mon Mar 13, 2017 7:31 pm
Forum: General Rate Laws
Topic: coefficients
Replies: 2
Views: 314

coefficients

when do the coefficients matter for the rate law?
eg aA --> bB how do you know if rate = [A]^a or just [A]?
my TA said something about mechanisms but im not completely sure
by Kim
Mon Mar 13, 2017 4:23 pm
Forum: Calculating Work of Expansion
Topic: Latm --> J
Replies: 1
Views: 289

Latm --> J

When calculating work using w=P∆V, shouldn't you always multiply by the 101.325 (J/Latm) number to put work in joules?
im just unsure since that number isn't in the equation.

thanks!
by Kim
Wed Mar 08, 2017 5:39 pm
Forum: *Organic Reaction Mechanisms in General
Topic: placement of the dipole (#4.28)
Replies: 1
Views: 269

placement of the dipole (#4.28)

in #28 in Chapter 4 of the organic textbook, you have to write the mechanism and the transition state
I understood it except this part:
Image
why is the positive dipole on the middle carbon as opposed to the carbon forming the bond with the H?
by Kim
Mon Mar 06, 2017 4:12 pm
Forum: Administrative Questions and Class Announcements
Topic: switch 14C and BL
Replies: 2
Views: 402

Re: switch 14C and BL

still looking for someone :)
by Kim
Thu Mar 02, 2017 2:13 pm
Forum: Administrative Questions and Class Announcements
Topic: switch 14C and BL
Replies: 2
Views: 402

switch 14C and BL

I'm in 14C next quarter and I was wondering if anyone in 14BL would be willing to switch places with me, as in you'd take 14C instead and i'd take BL. Thanks!
by Kim
Thu Mar 02, 2017 2:10 pm
Forum: *Organic Reaction Mechanisms in General
Topic: the line with two crosses
Replies: 1
Views: 208

the line with two crosses

what does the line with two crosses in it mean? the one placed next to delta G/H/etc
by Kim
Tue Feb 21, 2017 10:01 pm
Forum: Reaction Mechanisms, Reaction Profiles
Topic: pre equilibrium approach (question about something in the coursereader)
Replies: 1
Views: 269

pre equilibrium approach (question about something in the coursereader)

page 73 in the course reader discusses the pre equilibrium approach
(my question is under the pic)
Image
I just don't understand where the 1/2d[NO2]/dt came from and why that equals k2[N2O2][O2]
Thanks in advance!
by Kim
Tue Feb 14, 2017 5:12 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: 14.15a - writing cell diagram
Replies: 1
Views: 257

14.15a - writing cell diagram

heres the question:
Image

and the answer:
Image

can someone explain the role of AgBr? like why is it on the left side of the diagram and why did it get split up in the way it did...
by Kim
Mon Feb 13, 2017 9:16 am
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: deciding which is oxidized/reduced
Replies: 2
Views: 312

deciding which is oxidized/reduced

P. 162 in the course reader, #8 in winter 2016 midterm: "a standard electrochemical cell is made by placing a silver electrode into a 1.0M Ag+ solution and a cadmium electrode into a 1.0 M Cd2+ solution. What is the redox reaction and what is the maximum potential produced?" how would you ...
by Kim
Tue Feb 07, 2017 9:41 am
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: memory trick [ENDORSED]
Replies: 3
Views: 569

memory trick [ENDORSED]

I'm not sure if this helps anyone but it helps me so I figured I'd share: the anode is on the left and is where oxidation takes place while the cathode is on the right and it's where reduction takes place. all the words relating to the anode side come before alphabetically those on the cathode side:...
by Kim
Wed Feb 01, 2017 3:47 pm
Forum: Gibbs Free Energy Concepts and Calculations
Topic: state functions
Replies: 2
Views: 320

state functions

out of:
∆G
∆Ssurr
∆Ssys
∆H
q
w

which are state functions?
by Kim
Wed Feb 01, 2017 12:00 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: isothermal
Replies: 1
Views: 301

isothermal

does isothermal always mean:
• constant temperature
• ∆U=0
• so: q = -w
?
or is that just in specific cases
by Kim
Wed Jan 25, 2017 7:03 pm
Forum: Concepts & Calculations Using Second Law of Thermodynamics
Topic: favorability
Replies: 1
Views: 431

favorability

are all exothermic reactions favorable? and all endothermic not favorable?
by Kim
Tue Jan 17, 2017 9:38 pm
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: Isolated [ENDORSED]
Replies: 1
Views: 243

Isolated [ENDORSED]

Is it actually possible to have a perfect isolated system?
by Kim
Fri Jan 13, 2017 4:02 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: State Property
Replies: 1
Views: 168

State Property

Is heat a state property always or only when its at constant conditions? Why?

Thanks :)
by Kim
Sat Dec 03, 2016 12:36 am
Forum: Ionic & Covalent Bonds
Topic: least covalent character
Replies: 4
Views: 617

least covalent character

"which of the compounds below has bonds with the least covalent character?"
AgI , AgCl, AgF, AlCl3, BeCl2
answer is AgF
why not becl2? it's ionic?
by Kim
Fri Dec 02, 2016 7:00 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: Fall 2012 Final # 5C
Replies: 1
Views: 261

Fall 2012 Final # 5C

talking about the equation H2 + I2 <--> 2HI and asking whether or not the products or reactants are favored if something changes
one of them says "small amount of I2 added" and the answer says it doesn't favor either
why?
by Kim
Thu Dec 01, 2016 3:01 pm
Forum: Administrative Questions and Class Announcements
Topic: Bring to the final [ENDORSED]
Replies: 2
Views: 363

Re: Bring to the final [ENDORSED]

according to the course reader - that's it!
by Kim
Thu Dec 01, 2016 2:59 pm
Forum: Administrative Questions and Class Announcements
Topic: Memorization of Acids and Bases
Replies: 2
Views: 433

Re: Memorization of Acids and Bases

My TA suggested knowing all the strong acids and strong bases (I think theres 6 acids and 8 bases), so that you know every other one is weak
by Kim
Thu Dec 01, 2016 2:51 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: pressure change and the effect on K
Replies: 2
Views: 366

Re: pressure change and the effect on K

There is no inherent relationship between pressure and concentration so changing one doesnt change the other. Also, pressure doesn't inherently change volume, and a change in volume still doesn't change K
by Kim
Mon Nov 14, 2016 6:03 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: Quiz 3 Prep Fall 2015 Q#10
Replies: 1
Views: 274

Quiz 3 Prep Fall 2015 Q#10

"For the reaction at equilibrium, HCl (g) + I2 (s) <--> HI (g) + Cl2 (g), how will an increase in the pressure (by decreasing the volume) affect the concentration of Cl2?" the answer is that it decreases but I don't understand why :(
thanks in advance!
by Kim
Wed Nov 09, 2016 2:29 pm
Forum: Naming
Topic: ligand naming question [ENDORSED]
Replies: 2
Views: 336

ligand naming question [ENDORSED]

it says you put the ligand name before the TM metal but arent there many ligands? how do you know which to put first? (is this alphabetical?)
by Kim
Mon Oct 31, 2016 4:42 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: H2CBr2 Polarity
Replies: 2
Views: 271

H2CBr2 Polarity

Why is H2CBr2 polar? Wouldn't the 2 Br cancel and the 2 H cancel?
by Kim
Fri Oct 28, 2016 4:47 pm
Forum: Hybridization
Topic: sigma and pi bonds
Replies: 3
Views: 421

Re: sigma and pi bonds

there is a sigma bond in every bond
single bond - 1 sigma bond
double bond - 1 sigma, 1 pi
triple bond - 1 sigma, 2 pi
by Kim
Wed Oct 19, 2016 9:45 pm
Forum: Ionic & Covalent Bonds
Topic: Question 3.57 B
Replies: 1
Views: 174

Re: Question 3.57 B

Did you make sure your structure had the correct amount of electrons?
by Kim
Tue Oct 11, 2016 5:24 pm
Forum: Empirical & Molecular Formulas
Topic: Fall 2015 Quiz Prep question #5 [ENDORSED]
Replies: 3
Views: 515

Fall 2015 Quiz Prep question #5 [ENDORSED]

Can someone explain this to me? Sorry if this has already been answered elsewhere but I couldn't find it

"6.4g of a compound was burned in air and produced 8.80g CO2 and 7.20g H2O. Find the empirical formula of the compound."

the answer is CH4O
by Kim
Mon Oct 03, 2016 11:16 pm
Forum: Student Social/Study Group
Topic: Hitch Study Group
Replies: 12
Views: 1215

Re: Hitch Study Group

Hitch D! also down for this! should we make a facebook group chat or something?
by Kim
Wed Sep 28, 2016 1:38 pm
Forum: General Science Questions
Topic: Light as a Wave
Replies: 3
Views: 598

Re: Light as a Wave

Light has properties of both waves and particles,

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