## Search found 20 matches

Mon Feb 09, 2015 9:51 pm
Forum: Entropy Changes Due to Changes in Volume and Temperature
Topic: Monoatomic vs Linear - Midterm 2010, Question 4A
Replies: 2
Views: 500

### Monoatomic vs Linear - Midterm 2010, Question 4A

I was wondering why we use 3/2R instead of 5/2R for Cv value. Isn't Nitrogen gas, or N2 (g), linear, and thus 5/2R?
Sat Dec 13, 2014 7:11 pm
Forum: *Titrations & Titration Calculations
Topic: using the 5% rule
Replies: 3
Views: 4224

### Re: using the 5% rule

If you're talking about the 5% rule where you turn, for instance, [(2.0x10^-7)-x] into just [x], then that depends on if the Ka or Kb is less than or equal to 10^-5. If it's 10^-4, and you're really not feeling up to using the quadratic equation, you can use the shortcut, and see whether your x valu...
Thu Dec 11, 2014 5:47 pm
Forum: Acidity & Basicity Constants and The Conjugate Seesaw
Topic: 2009 Final Exam, Problem #7
Replies: 1
Views: 618

### 2009 Final Exam, Problem #7

Ok guys, so after a lot of thought, I finally figured out the problem. I know a lot of people have been having issues with this problem, so I thought I'd help out and explain it. So here's the problem: At what concentration of acetic acid does autoprotolysis of water need to be taken into account? A...
Thu Dec 11, 2014 12:25 pm
Forum: Acidity & Basicity Constants and The Conjugate Seesaw
Topic: Fall 2009 Practice Final, Problem 7
Replies: 1
Views: 411

### Fall 2009 Practice Final, Problem 7

Hi guys, I was having trouble understanding problem number 7 on the fall 2009 Final. I was hoping someone could break it down for me and explain it. So here's the problem: At what concentration of acetic acid does autoprotolysis of water need to be taken into account? Acetic acid, Ka = 1.8*10^-5. Ex...
Thu Dec 04, 2014 11:21 pm
Forum: Ideal Gases
Topic: How to find Kp
Replies: 1
Views: 1609

### Re: How to find Kp

There are two ways you can convert from Kc to Kp. It kind of depends of how you want to tackle the question, as well as the information given. If you are, for example, given sufficient information initial and equilibrium concentrations to find the value of x, but are asked to find the equilibrium co...
Tue Dec 02, 2014 5:38 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Example 10.8
Replies: 1
Views: 302

### Re: Example 10.8

This problem was very confusing because although the question specifically stated to have the equilibrium values in terms of molarity, the book left it in terms of pressure. As for why they switched to pressure, it's because the equilibrium constant was given in terms of K, as opposed to Kc. Profess...
Tue Dec 02, 2014 5:33 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Quiz 3 #10
Replies: 8
Views: 1107

### Re: Quiz 3 #10

In the book in Example 10.8, when a specific unit was not given, and they converted from moles to pressure, they put it in bars, so that's what I'm going with. So Patrick, are your three answers in atm, bar, and Torr? And do you have significantly altered answers when for each set?
Tue Dec 02, 2014 5:14 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Quiz 3 #10
Replies: 8
Views: 1107

### Re: Quiz 3 #10

How do you know which unit of pressure to use? Like how do we tell when to use atm, bar, etc.? And does it even matter?
Tue Dec 02, 2014 2:01 am
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Quiz #2, Problem 10
Replies: 7
Views: 2350

### Re: Quiz #2, Problem 10

I figured it out, I think. So after you set your ICE Table, you find the value for K by using the equilibrium amounts given, and you get a value that rounds up to 32. From here, the equation looks like: 32 = (7.6+x)(4.9+x)/(.54-2x)^2 Once you solve for x, you'll eventually end up with the following ...
Mon Dec 01, 2014 8:11 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Quiz #2, Problem 10
Replies: 7
Views: 2350

### Quiz #2, Problem 10

I was working on the yellow book, and I can't figure this question out. Bromine chloride, bromine, and chlorine gas have reached equilibrium in a container at 500K according to the reaction, 2BrCl =Br2+Cl2. Equilibrium partial pressures are 1.08 bar for BrCl, 4.9 bar Br2, and 7.6 bar Cl2. Half the B...
Sun Nov 30, 2014 4:45 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Module 2 Question
Replies: 1
Views: 322

### Module 2 Question

This was the only question on the module I was unsure of, so I wanted to just verify if I got the answer right for this question. Complete the following. If Q < 1 then ____ A. The reaction will proceed towards right (towards the products). B. The reaction will proceed towards left (towards the react...
Fri Nov 28, 2014 9:04 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: HW 10.47.a solution manual error?
Replies: 3
Views: 537

### Re: HW 10.47.a solution manual error?

I think it's a typo... If they produced wrong answers, Professor Lavelle would have caught it and posted it on his Solution Manual Errors page on the site. Because the right answers were given, I think he didn't notice the 2.1.
Fri Nov 28, 2014 8:47 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Module Question
Replies: 2
Views: 400

### Module Question

I have no idea how to do this one. Any help would be appreciated. Using the ideal gas law, PV = nRT, as an approximation for a real gas, write an expression showing how to convert the concentration of a gas to a pressure value. A. P = nRT/V B. V = nRT/P C. P/n = RT/V D. P/R = nT/V E. None of the Above
Fri Nov 28, 2014 8:31 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Conceptual Question about Equilibrium Constants
Replies: 1
Views: 403

### Conceptual Question about Equilibrium Constants

So I came across this question in the first Module, and I was kinda confused.

Are solvents included in equilibrium constant expressions?
A. No
B. Yes
C. Sometimes
D. Not always
E. None of the above
Fri Nov 28, 2014 7:53 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: HW 10.39
Replies: 3
Views: 3659

### Re: HW 10.39

Ok, so I'm gonna explain the problem to you, as well as show you my work. The first thing to notice here in the problem is that the question is asking for the value of K, not Kc. However, we are given sufficient information to only find molar concentrations from the formula M=n/V. Therefore, in this...
Sun Nov 09, 2014 2:32 am
Forum: Hybridization
Topic: S Character of Hybrids
Replies: 2
Views: 582

### Re: S Character of Hybrids

I was confused by this too, so I looked this up. Short: Apparently the s-character of a hybrid is simply referring to its shape; the s orbital is commonly denoted as a circle (in reality it's a complex wave function), and the p orbital has a kind of figure eight shape. Long story short, when the s a...
Sat Nov 08, 2014 9:42 pm
Forum: *Molecular Orbital Theory (Bond Order, Diamagnetism, Paramagnetism)
Topic: Bonding in Heteronuclear Diatomic Molecules
Replies: 1
Views: 500

### Bonding in Heteronuclear Diatomic Molecules

I was just wondering, will we asked to write down the molecular orbital diagram for a heteronuclear diatomic molecule on the midterm? Also, it's essentially, the same thing as homonuclear, in terms of the overall structure of the diagram, right? Is the only difference that (obviously) the number of ...
Sat Nov 08, 2014 9:36 pm
Forum: Hybridization
Replies: 1
Views: 356

Did Professor Lavelle say we ever had to draw 3-D representations of hybridization? Or will all we have to do is write the hybridized orbitals like sp3, sp, sp3d?
Sat Oct 18, 2014 7:04 pm
Forum: Molarity, Solutions, Dilutions
Topic: G-25
Replies: 1
Views: 635

### G-25

I know there was already an answer posted to this question, but I'm still confused. Can someone explain to me how to solve it? Here is the problem: Concentrated hydrochloric acid is 37.50% HCL by mass and has a density of 1.205 cm^-3. What volume (in mL) of concentrated hydrochloric acid must be use...
Sat Oct 18, 2014 6:05 pm
Forum: Properties of Light
Topic: Spectropic Series
Replies: 3
Views: 453

### Re: Spectropic Series

I was a little confused about this as well, so I looked it up on the Google as well. What I found was that we can't be expected to know more than that each series shares the same value for n1. It would be also probably be prudent to memorize the n1 values for each series.