## Search found 33 matches

Sun Mar 19, 2017 12:48 pm
Forum: Administrative Questions and Class Announcements
Topic: midterm vs final question
Replies: 1
Views: 302

### 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...
Fri Mar 17, 2017 2:21 pm
Forum: *Amines
Topic: 2.35
Replies: 2
Views: 619

### 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...
Thu Mar 16, 2017 2:21 pm
Forum: Phase Changes & Related Calculations
Topic: reversible process
Replies: 3
Views: 333

### 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?
Tue Mar 14, 2017 8:08 am
Forum: General Rate Laws
Topic: coefficients
Replies: 2
Views: 302

### 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...
Mon Mar 13, 2017 7:31 pm
Forum: General Rate Laws
Topic: coefficients
Replies: 2
Views: 302

### 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
Mon Mar 13, 2017 4:23 pm
Forum: Calculating Work of Expansion
Topic: Latm --> J
Replies: 1
Views: 273

### 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!
Wed Mar 08, 2017 5:39 pm
Forum: *Organic Reaction Mechanisms in General
Topic: placement of the dipole (#4.28)
Replies: 1
Views: 259

### 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:

why is the positive dipole on the middle carbon as opposed to the carbon forming the bond with the H?
Mon Mar 06, 2017 4:12 pm
Forum: Administrative Questions and Class Announcements
Topic: switch 14C and BL
Replies: 2
Views: 389

### Re: switch 14C and BL

still looking for someone :)
Thu Mar 02, 2017 2:13 pm
Forum: Administrative Questions and Class Announcements
Topic: switch 14C and BL
Replies: 2
Views: 389

### 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!
Thu Mar 02, 2017 2:10 pm
Forum: *Organic Reaction Mechanisms in General
Topic: the line with two crosses
Replies: 1
Views: 197

### the line with two crosses

what does the line with two crosses in it mean? the one placed next to delta G/H/etc
Tue Feb 21, 2017 10:01 pm
Forum: Reaction Mechanisms, Reaction Profiles
Replies: 1
Views: 260

page 73 in the course reader discusses the pre equilibrium approach
(my question is under the pic)

I just don't understand where the 1/2d[NO2]/dt came from and why that equals k2[N2O2][O2]
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: 243

### 14.15a - writing cell diagram

heres the question:

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...
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: 297

### 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 ...
Tue Feb 07, 2017 9:41 am
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: memory trick [ENDORSED]
Replies: 3
Views: 546

### 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:...
Wed Feb 01, 2017 3:47 pm
Forum: Gibbs Free Energy Concepts and Calculations
Topic: state functions
Replies: 2
Views: 303

### state functions

out of:
∆G
∆Ssurr
∆Ssys
∆H
q
w

which are state functions?
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: 288

### isothermal

does isothermal always mean:
• constant temperature
• ∆U=0
• so: q = -w
?
or is that just in specific cases
Mon Jan 30, 2017 12:19 pm
Forum: Calculating Standard Reaction Entropies (e.g. , Using Standard Molar Entropies)
Topic: Standard Molar Entropies of Aqueous Solutions
Replies: 1
Views: 392

### Re: Standard Molar Entropies of Aqueous Solutions

Wed Jan 25, 2017 7:03 pm
Forum: Concepts & Calculations Using Second Law of Thermodynamics
Topic: favorability
Replies: 1
Views: 403

### favorability

are all exothermic reactions favorable? and all endothermic not favorable?
Tue Jan 17, 2017 9:38 pm
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: Isolated [ENDORSED]
Replies: 1
Views: 232

### Isolated[ENDORSED]

Is it actually possible to have a perfect isolated system?
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: 163

### State Property

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

Thanks :)
Sat Dec 03, 2016 12:36 am
Forum: Ionic & Covalent Bonds
Topic: least covalent character
Replies: 4
Views: 559

### least covalent character

"which of the compounds below has bonds with the least covalent character?"
AgI , AgCl, AgF, AlCl3, BeCl2
why not becl2? it's ionic?
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: 252

### 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?
Thu Dec 01, 2016 3:01 pm
Forum: Administrative Questions and Class Announcements
Topic: Bring to the final [ENDORSED]
Replies: 2
Views: 346

### Re: Bring to the final[ENDORSED]

according to the course reader - that's it!
Thu Dec 01, 2016 2:59 pm
Forum: Administrative Questions and Class Announcements
Topic: Memorization of Acids and Bases
Replies: 2
Views: 408

### 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
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: 349

### 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
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: 268

### 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 :(
Wed Nov 09, 2016 2:29 pm
Forum: Naming
Topic: ligand naming question [ENDORSED]
Replies: 2
Views: 315

### 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?)
Mon Oct 31, 2016 4:42 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: H2CBr2 Polarity
Replies: 2
Views: 249

### H2CBr2 Polarity

Why is H2CBr2 polar? Wouldn't the 2 Br cancel and the 2 H cancel?
Fri Oct 28, 2016 4:47 pm
Forum: Hybridization
Topic: sigma and pi bonds
Replies: 3
Views: 401

### 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
Wed Oct 19, 2016 9:45 pm
Forum: Ionic & Covalent Bonds
Topic: Question 3.57 B
Replies: 1
Views: 167

### Re: Question 3.57 B

Did you make sure your structure had the correct amount of electrons?
Tue Oct 11, 2016 5:24 pm
Forum: Empirical & Molecular Formulas
Topic: Fall 2015 Quiz Prep question #5 [ENDORSED]
Replies: 3
Views: 493

### 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."

Mon Oct 03, 2016 11:16 pm
Forum: Student Social/Study Group
Topic: Hitch Study Group
Replies: 12
Views: 1173

### Re: Hitch Study Group

Hitch D! also down for this! should we make a facebook group chat or something?
Wed Sep 28, 2016 1:38 pm
Forum: General Science Questions
Topic: Light as a Wave
Replies: 3
Views: 585

### Re: Light as a Wave

Light has properties of both waves and particles,