## Search found 10 matches

Sat Mar 18, 2017 10:20 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Number 5B from 2015 Final
Replies: 2
Views: 335

### Re: Number 5B from 2015 Final

You want to find the maximum cell potential, you want the largest, positive E˚cell possible. Since: Cd2+ + 2e- --> Cd(s) E˚= -0.40V Ag+ + 1e= --> Ag(s) E˚= +0.80V Flipping the Cd reaction would give the largest E˚cell since you would reverse the sign to E˚= +0.40, it would be the anode since the Cd ...
Wed Mar 08, 2017 12:33 pm
Forum: Administrative Questions and Class Announcements
Topic: Quiz 3 Winter 2017
Replies: 183
Views: 16475

### Re: Quiz 3 Winter 2017

For number 5, how do we know the first step is the slow one? Also, could someone explain when and how to use iso- in naming? Or just how to do #1? For 5, the first step is the slow one because it involves breaking two bonds (Carbon-carbon double bond and the H-Br bond). Step two only involves the b...
Sun Mar 05, 2017 12:27 pm
Forum: Administrative Questions and Class Announcements
Topic: Quiz 3 Winter 2017
Replies: 183
Views: 16475

### Re: Quiz 3 Winter 2017

Blake_Katsev_2E wrote:Shouldnt number 4 be 5-butyl instead of 4-butyl?

If you start counting at the top H3C then go around counterclockwise, you should get 4-butyl.
Tue Feb 21, 2017 10:48 pm
Forum: Administrative Questions and Class Announcements
Topic: Quiz 2 Winter 2017
Replies: 160
Views: 15732

### Re: Quiz 2 Winter 2017

Hi, can someone show me how they did #7, I know you use the first order integrated rate law, but when I work it out I am not getting the answer that is posted. ln[A] = -kt+ln[A](initial) ln(0.622M) = -k(22min) + ln(0.773M) ln(0.622M/0.773M) = -k(22min) -0.00988min^(-1) = -k k= 9.88 *10^(-3) min^(-1)
Tue Feb 14, 2017 5:18 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: What's the difference between a Galvanic and Voltaic Cell?
Replies: 1
Views: 463

### Re: What's the difference between a Galvanic and Voltaic Cell?

Galvanic and Voltaic Cell are just two names for the same thing
Sun Feb 12, 2017 10:28 pm
Forum: Balancing Redox Reactions
Topic: HW 14.3d
Replies: 1
Views: 210

### Re: HW 14.3d

The Cl2 would be both the oxidizing and the reducing agent.
Sun Feb 05, 2017 10:57 pm
Forum: Balancing Redox Reactions
Topic: Help on problem 14.17
Replies: 4
Views: 577

### Re: Help on problem 14.17

a.) MnO4-(aq) + H+(aq) + 5e- Mn2+(aq) + 4H2O(l) (cathode)
5[Fe2+(aq) Fe3+(aq) + e-] (anode)

b.) MnO4-(aq) + 5Fe2+(aq) + 8H+(aq) Mn2+(aq) +5Fe3+(aq) +4H2O(l)
Sun Jan 29, 2017 9:26 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Standard enthalpies of formation
Replies: 3
Views: 491

### Re: Standard enthalpies of formation

You can use either equation, but because the equation 2C + O2 --> 2CO is for two moles of CO, you would need to multiply the ∆H°by 2. Then you should end up getting the same answer.
Sun Jan 22, 2017 3:55 pm
Forum: Phase Changes & Related Calculations
Topic: 8.117 [ENDORSED]
Replies: 1
Views: 263

### Re: 8.117[ENDORSED]

∆U = ∆H - P∆V

-P∆V = -∆RT
=-(2/3mol)(8.314 J*K^(-1)*mol^(-1))(298K)
=-1651.7 J
=-1.65 kJ

∆H= (1/3)(-318kJ)
= -106kJ

∆U = -106kJ – 1.65kJ
=-108kJ
Sun Jan 15, 2017 10:39 pm
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: Heat capacity
Replies: 1
Views: 218

### Re: Heat capacity

Monatomic molecules only have translational thermal energy, but more complex molecules also have rotation and vibration motions which absorb energy. Therefore, the energy is divided up between these motions. Since only translational energy contributes to temperature increase, the temperature increas...