## Search found 21 matches

Sat Mar 18, 2017 8:15 am
Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
Topic: Nernst Equation
Replies: 1
Views: 298

### Nernst Equation

When using the Nernst Equation, how do I know whether to use
E(cell)=E(cell)0 - RT/nF lnQ
or
E(cell)=E(cell)0 - 0.05916/n log Q?
In the practice finals in the back of the course reader, some problems use the first equation while others use the second.
Do they give the same result?

Thank you!
Tue Mar 07, 2017 10:58 am
Forum: *Alkanes
Topic: #1 quiz 3 preparation
Replies: 2
Views: 473

### #1 quiz 3 preparation

Name the compound shown below. ..........................................CH(CH3)2 .............................................I CH3 CH2 CH2 CH2 CH2 CH2 CH CH2 CH2 CH3 (ignore the periods) The answer for this problem is 4-isopropyldecane or 4-(1-methylethyl) decane but I don't understand how to come...
Sat Mar 04, 2017 9:08 am
Forum: Administrative Questions and Class Announcements
Replies: 3
Views: 457

### Re: Friday Review Session Broadcast

I think this is the video that was recorded during the review session!

viewtopic.php?f=160&t=20107
Mon Feb 20, 2017 8:18 pm
Forum: Second Order Reactions
Topic: Homework Problem 15.19
Replies: 3
Views: 466

### Re: Homework Problem 15.19

I am also not understanding this part of the problem. The solution manual states that the rate is increased by (3.02/1.25)^2 however I am not seeing how the rate is increased by this amount.

Thank you!
Mon Feb 13, 2017 8:51 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Replies: 1
Views: 277

How do I know when to add Platinum to a cell diagram?
I thought platinum was added when there were no solids in the equation. However for homework problem 14.13 part b, the cell diagram is
Pt(s) I I^-(aq) I I2(s) II Ce^-4(aq), Ce^3+ (aq) I Pt(s)
Thu Feb 09, 2017 10:20 pm
Forum: Balancing Redox Reactions
Topic: Homework 14.1
Replies: 3
Views: 442

### Homework 14.1

H^{+}(aq) + Cr_{2}O_{7}^{2-} (aq) + C_{2}H_{5}OH(aq) \rightarrow Cr^{3+}(aq) + C_{2}H_{4}O(aq) + H_{2}O(l) Identify the elements undergoing changes in oxidation state and indicate the initial and final oxidation numbers for these elements. The solutio...
Mon Jan 30, 2017 12:57 pm
Forum: Gibbs Free Energy Concepts and Calculations
Topic: Quiz 1 prep #9
Replies: 2
Views: 380

### Quiz 1 prep #9

A sample of 1 mol of gas initially at 1 atm and 298K is heated at constant pressure to 350K, then the gas is compressed isothermally to its initial volume and finally it is cooled to 298K at constant volume. Which of the following values is zero? -Delta S of surrounding and Delta G -Delta S of syste...
Mon Jan 23, 2017 10:52 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: homework 8.49
Replies: 2
Views: 380

### homework 8.49

question: Oxygen difluoride is a colorless, very poisonous fas that reacts rapidly with water vapor to produce O2, HF, and heat: OF2 + H2O ---> O2 + 2HF delta H = -318kJ What is the change in internal energy for the reaction of 1.00 mol OF2? The solution manual uses 298K as temperature. I was wonder...
Wed Jan 18, 2017 4:37 pm
Forum: Calculating Work of Expansion
Topic: Homework 8.9 [ENDORSED]
Replies: 3
Views: 630

### Homework 8.9[ENDORSED]

A piston confines 0.200 mol Ne(g) in 1.20 L at 25 degrees C. Two experiments are performed. (a) The gas is allowed to expand through an additional 1.20 L against a constant pressure of 1.00 atm. (b) The gas is allowed to expand reversibly and isothermally to the same final volume. Which process does...
Thu Jan 12, 2017 10:48 pm
Forum: Phase Changes & Related Calculations
Replies: 14
Views: 1731

I personally really liked the UA office hours because they are students that have taken this class before. So they tend to know what topics we would struggle in and they explain it in a way that is easy to understand. Also, UA sessions are done in small groups so it was easy to get my questions answ...
Tue Nov 29, 2016 12:29 am
Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
Topic: 12.61
Replies: 4
Views: 860

### 12.61

problem:Find the initial concentration of the weak acid or base in each of the following aqueous solutions: (a) a solution of HClO with pH 4.60 In the solution manual, it says "Let x=nominal concentration of HClO" What is the nominal concentration and why do we use this instead of the ICE ...
Sat Nov 26, 2016 8:04 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: change in temperature
Replies: 2
Views: 426

### change in temperature

How does changing temperature affect a reaction?
I know that if a reaction is endothermic then it will favor products and if a reaction is exothermic it favors reactants forming.
But what does that exactly mean?

Thank you!
Wed Nov 16, 2016 10:18 pm
Forum: Naming
Topic: Formula
Replies: 1
Views: 251

### Formula

When writing the formula for a complex compound, does the order of the ligands written matter?
Wed Nov 09, 2016 8:41 pm
Forum: *Molecular Orbital Theory (Bond Order, Diamagnetism, Paramagnetism)
Topic: MO diagram [ENDORSED]
Replies: 2
Views: 370

### MO diagram[ENDORSED]

When drawing the molecular orbital diagram, why do we fill up the pi before the sigma?
For example, in the diagram for N2, pi2p would be filled up before sigma2p.
Tue Nov 01, 2016 9:28 pm
Forum: Sigma & Pi Bonds
Topic: pi bonds
Replies: 1
Views: 327

### pi bonds

When we write the hybridization of pi bonds, why do we only mention the p orbital?
Fri Oct 28, 2016 12:10 pm
Forum: Ionic & Covalent Bonds
Topic: Ionic character
Replies: 1
Views: 327

### Ionic character

How do I know what molecule/compound has more ionic character than another?
Thu Oct 20, 2016 10:29 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Electron configuration for ions [ENDORSED]
Replies: 2
Views: 361

### Electron configuration for ions[ENDORSED]

If we are writing the electron configuration of an ion such as Cl-, then is it [Ar] or [Ne] 3s2 3p6?
Wed Oct 12, 2016 7:13 pm
Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
Topic: Significant Figures
Replies: 4
Views: 667

### Significant Figures

What is the wavelength of the radiation emitted when an electron transitions from n = 4 to n=3?
I understand how to solve this question, however how many significant figures should the answer be?
Tue Oct 04, 2016 11:31 pm
Forum: Einstein Equation
Topic: HW chapter 1 problem 23 [ENDORSED]
Replies: 2
Views: 596

### HW chapter 1 problem 23[ENDORSED]

Problem: The y-ray photons emitted by the nuclear decay of a technetium-99 atom used in radiopharmaceuticals have an energy of 140.511keV. Calculate the wavelength of these y-rays. The solution manual says that in order to convert eV to Joules we have to multiply the eV by 1.6022*10^-19. I was wonde...
Fri Sep 30, 2016 2:53 pm
Forum: Student Social/Study Group
Topic: De Neve Study Group
Replies: 35
Views: 3010

### Re: De Neve Study Group

I'm in Dogwood and I'm definitely interested!! Let me know if you guys are meeting!
Mon Sep 26, 2016 11:13 pm
Forum: Molarity, Solutions, Dilutions
Topic: Question on G25
Replies: 5
Views: 853

### Re: Question on G25

For the solution above, is 0.050M necessary to figure out the answer to this problem?