## Search found 22 matches

Sun Mar 06, 2016 11:11 am
Forum: *Electrophiles
Topic: Memory Tips
Replies: 8
Views: 1170

### Re: Memory Tips

These are all really good tips! It would also be helpful to just memorize some of the major ones, considering all the ones on the quiz were common ones we had seen before.
Sat Feb 27, 2016 12:08 pm
Forum: *Cycloalkanes
Topic: Quiz 3 Preparation 1, Number 5
Replies: 3
Views: 629

### Quiz 3 Preparation 1, Number 5

For Quiz 3 Preparation 1, Number 5, why is iodo given the number one, rather than bromo? Shouldn't it be 1-bromo-3-iodocyclohexane to be alphabetical and the be given the lowest number?
Sat Feb 20, 2016 12:33 pm
Forum: Arrhenius Equation, Activation Energies, Catalysts
Topic: Problem 15.63
Replies: 1
Views: 326

### Problem 15.63

For this problem, in the solution manual, it subtracts an extra 0.59 at the end of the equation. Why is this?
Mon Feb 15, 2016 9:14 pm
Forum: Administrative Questions and Class Announcements
Topic: Quiz 2 Winter 2016
Replies: 18
Views: 7187

### Re: Quiz 2 Winter 2016

We don't need to know steady state for the quiz
Sun Feb 07, 2016 4:48 pm
Forum: Entropy Changes Due to Changes in Volume and Temperature
Topic: Change in entropy equation when pressure changes
Replies: 1
Views: 531

### Change in entropy equation when pressure changes

I was reviewing my notes from different chemistry reviews and one TA had said that when our pressure changes, our equation for entropy change is ΔS=nRln(P2/P1) but another one had written ΔS=nRln(P1/P2). Just wanted to clarify which equation is correct. Thanks!
Mon Feb 01, 2016 10:06 am
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: 14.15
Replies: 2
Views: 299

### 14.15

Why for part a of 14.15 is AgBr separated into Ag and then AgBr for the two half-reactions and not just Ag and then Br?
Sun Jan 24, 2016 9:35 pm
Forum: Third Law of Thermodynamics (For a Unique Ground State (W=1): S -> 0 as T -> 0) and Calculations Using Boltzmann Equation for Entropy
Topic: Exponent for the Number of Orientations
Replies: 1
Views: 275

### Exponent for the Number of Orientations

In some of the problems for the chapter 9 homework, such as 9.75, they put the exponent for the number of orientations as 6.02 x 10^23. Why is this?
Sun Jan 24, 2016 9:26 pm
Forum: Thermodynamic Definitions (isochoric/isometric, isothermal, isobaric)
Topic: Useful Summary of Thermodynamic Definitions
Replies: 34
Views: 14675

### Re: Useful Summary of Thermodynamic Definitions

Thank you! Just to clarify, are the only terms that are NOT state functions, work and heat?
Thu Jan 21, 2016 10:09 pm
Forum: Concepts & Calculations Using Second Law of Thermodynamics
Topic: Change in temperature and its effect on entropy
Replies: 1
Views: 248

### Change in temperature and its effect on entropy

For problem 9.1 on the homework, it says that if the increase from 20 to 30 degrees celsius would make the delta S be less. I understand that if the temperature goes up, then the change in entropy goes down because of the equation q/T. But if the temperature is going up, then isn't there more chance...
Mon Jan 18, 2016 3:57 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Correction for 8.101
Replies: 1
Views: 337

### Correction for 8.101

Just wanted to point out that in the solution manual for problem 8.101, it says that the enthalpy (in kJ) after multiplying (0.030 mol SO2)x(-197.78 kJ/ 2 mol SO2) is -2966.7 kJ when it should actually be -2.9967. The rest of the problem is correct, but in case anyone else thought that they were get...
Wed Jan 13, 2016 10:36 am
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: 8.73 Bond Enthalpy of Benzene
Replies: 4
Views: 4365

### 8.73 Bond Enthalpy of Benzene

For problem 8.73, I'm looking at both the tables, 8.6 and 8.7, and neither have included the bond enthalpy for benzene and, looking at the notes from my discussion and at the solution manual, they both use an already calculated total value for benzene. How did they get this value?
Sun Jan 10, 2016 6:50 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Standard Enthalpy of Formation (8.63)
Replies: 1
Views: 372

### Re: Standard Enthalpy of Formation (8.63)

The correct value of K2S is -471.5 kJ/mol. As for the difference found in problem 62 and 59 between having kJ/mol and kJ, I think that 59 should also be kJ, since the standard enthalpy values are being multiplied by the number of moles, which should cancel out the moles on the denominator and only l...
Fri Dec 04, 2015 11:08 am
Forum: *Making Buffers & Calculating Buffer pH (Henderson-Hasselbalch Equation)
Topic: Henderson-Hasselbalch for buffers only?
Replies: 1
Views: 358

### Henderson-Hasselbalch for buffers only?

Should we only use the Henderson-Hasselbalch Equation when dealing with buffers? Or are there other times when we could use it?
Sun Nov 29, 2015 2:01 pm
Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
Topic: Problem 12.65
Replies: 1
Views: 396

### Problem 12.65

For number 65 on the chapter 12 homework, they ask for an equation to justify why an aqueous solution with a given salt has a pH greater than, less than, or equal to 7 and the equations in the solution manual doesnt include the elements like Br or K. Why is that?
Mon Nov 16, 2015 8:58 pm
Forum: Naming
Topic: Ending for Coordination Compounds
Replies: 1
Views: 329

### Ending for Coordination Compounds

How do you know if the coordination compound should end with an -ate or -ide at the end?
Wed Nov 11, 2015 5:27 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: Conditions favoring production - pressure
Replies: 6
Views: 813

### Re: Conditions favoring production - pressure

So does any change in pressure (an increase or decrease) result in favoring the side with the fewer amount of moles?
Tue Nov 03, 2015 5:08 pm
Forum: *Molecular Orbital Theory (Bond Order, Diamagnetism, Paramagnetism)
Topic: Homo and Lumo
Replies: 1
Views: 281

### Re: Homo and Lumo

I'm not sure which one would radiate visible light. But HOMO is the Highest Occupied Molecular Orbital while LUMO is the Lowest Unoccupied Molecular Orbital. So when looking at your molecular orbital diagram, let's say for B2, then the LUMO would be the σPz of the 2p level, as there are no electrons...
Wed Oct 28, 2015 4:19 pm
Forum: Ionic & Covalent Bonds
Topic: How to tell from whether it is covalent or ionic
Replies: 3
Views: 571

### Re: How to tell from whether it is covalent or ionic

Usually, if the electronegativity difference is above 2, then it is considered ionic, but if the difference less than 1.5, then it's usually covalent. However, you would need to be given the electronegativity values to do this. So, if you're given the molecular formulas (such as HCl or HI), one of t...
Fri Oct 23, 2015 8:48 am
Forum: Sigma & Pi Bonds
Topic: Hybridization
Replies: 2
Views: 506

### Re: Hybridization

Yes, because they both have 4 regions of electron density and the shells for each of the atoms bonded to it are filled, they both have hybridizations of sp3
Wed Oct 14, 2015 12:30 pm
Forum: Lewis Structures
Topic: Lewis Structure- Expanded Octate
Replies: 1
Views: 253

### Re: Lewis Structure- Expanded Octate

Hi! So I'm not positive on how it changes the elements' properties exactly, but for the first question, you know that an expanded octet (having more than 8 electrons around one atom) can be used for elements that can utilize the d-orbital, such as phosphorus, silicon, chlorine, and sulfur- they are ...
Tue Oct 06, 2015 8:31 pm
Forum: Heisenberg Indeterminacy (Uncertainty) Equation
Topic: Textbook Example 1.7 clarification
Replies: 3
Views: 463

### Re: Textbook Example 1.7 clarification

How did they get "h" to be 1.05457 x 10 ^-34?
Fri Oct 02, 2015 2:05 pm
Forum: Photoelectric Effect
Topic: Post Module Assessment Question
Replies: 1
Views: 316

### Post Module Assessment Question

If the work function is given in kJ/mol, do we ignore the per mole part and just convert it to Joules?