## Search found 22 matches

Sat Mar 18, 2017 8:43 pm
Forum: *Cycloalkenes
Topic: Order of naming
Replies: 6
Views: 1053

### Re: Order of naming

You want the set of numbers that has the lowest number. 1 is the lowest number, so use the set that has 1, which is 1,6. Side note: you'd think it was 2,3 because that has lower numbers overall but IUPAC doesn't have a "lowest sum" rule or anything (ie 2+3 is less than 1+6), just lowest n...
Fri Mar 17, 2017 10:57 pm
Forum: Reaction Mechanisms, Reaction Profiles
Topic: Quiz 2 question
Replies: 3
Views: 425

### Re: Quiz 2 question

If you're talking about graphing deltaG reaction and deltaG transition, deltaG reaction is the distance between products and reactants and deltaG transition is the distance from the reactant to the top of the transition state
Thu Mar 09, 2017 10:31 am
Forum: *Cycloalkenes
Topic: Order of naming
Replies: 6
Views: 1053

### Re: Order of naming

You want the set of numbers that has the lowest number. 1 is the lowest number, so use the set that has 1, which is 1,6. Side note: you'd think it was 2,3 because that has lower numbers overall but IUPAC doesn't have a "lowest sum" rule or anything (ie 2+3 is less than 1+6), just lowest nu...
Tue Feb 28, 2017 8:13 pm
Forum: *Electrophiles
Topic: 4.11, 4.13
Replies: 2
Views: 455

### Re: 4.11, 4.13

I don't think we've gone over those things in class besides alkenes and alkynes so I'd say we don't need to know them at this point
Sat Feb 25, 2017 12:24 am
Forum: Arrhenius Equation, Activation Energies, Catalysts
Topic: Quiz prep 2 #11
Replies: 4
Views: 632

### Re: Quiz prep 2 #11

They might show up on the final so I'd still do them even if they don't show up on quiz 2.
Fri Feb 17, 2017 8:22 pm
Forum: Calculating Standard Reaction Entropies (e.g. , Using Standard Molar Entropies)
Topic: standard molar entropy
Replies: 2
Views: 512

### Re: standard molar entropy

Also the reason why we only look at residual entropy at 0K is because at 0K there is no vibrational entropy. I think the increasing molar mass has to do with generally, more molar mass means more complexity which means more interactions between the atoms which leads to vibrations but at 0K it just d...
Fri Feb 10, 2017 11:15 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Question 7.27, Gas constant temperature units
Replies: 9
Views: 1625

### Re: Question 7.27, Gas constant temperature units

Yes, you usually save doing sig figs till the very end. Sometimes solutions will round ahead of time because they probably don't want to have to write out the entire number, but your end answer should be the same.
Fri Feb 03, 2017 4:20 pm
Forum: Concepts & Calculations Using First Law of Thermodynamics
Topic: 8.117
Replies: 1
Views: 307

### 8.117

One step in the production of hydrogen as a fuel is the reaction of methane with water vapor: CH4(g)+H2O(g)->CO2(g)+3H2(g) deltaH=-318kJ What is the change in internal energy for the production of 1.00 mol H2? In the solution manual it says there's a net production of 2/3 mole of gas. Where does the...
Sat Jan 28, 2017 11:57 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Homework 8.65
Replies: 2
Views: 562

### Homework 8.65

Calculate the standard enthalpy of formation of dinitrogen pentoxide from the following data 2NO(g)+O2(g)->2NO2(g) H=-114.1 kJ 4NO2(g)+O2(g)->2N2O5 H=-110.2kJ and from the standard enthalpy of formation of nitric oxide, NO (see Appendix 2A) I'm confused how to know what is needed in the final reacti...
Thu Jan 19, 2017 10:29 am
Forum: General Science Questions
Topic: 2 different R constants?
Replies: 2
Views: 651

### Re: 2 different R constants?

.0821 has units L*atm/(K*mol) ad 8.314 has units J/(K*mol) so depending on what the problem is asking and what units are used in the problem, you can determine which R to use
Fri Jan 13, 2017 11:41 am
Forum: Administrative Questions and Class Announcements
Topic: Chem Final [ENDORSED]
Replies: 6
Views: 1231

### Re: Chem Final[ENDORSED]

Will we be receiving our finals back? If so, when and how?
Sat Dec 03, 2016 1:28 pm
Forum: *Titrations & Titration Calculations
Topic: Chapter 13 #35
Replies: 3
Views: 680

### Re: Chapter 13 #35

I think the 1.5x10^-3 is from 2.5x10^-3 mol CH3COOH reacting with 1.0x10^-3 mol OH-, so you subtract 1.0x10^-3 from 2.5x10^-3

But then I don't get how 1.0x10^-3 mol OH- is changed to 1.0x10^-3 mol CH3CO2...
Wed Nov 23, 2016 2:48 pm
Forum: Non-Equilibrium Conditions & The Reaction Quotient
Topic: 11.67
Replies: 1
Views: 428

### 11.67

The reaction 2 HCl(g)-> H2(g)+Cl2(g) has K=3.2x10^-34 at 298K. The initial partial pressures are H2, 1.0 bar; HCl, 2.0 bar; and Cl2, 3.0 bar. At equilibrium there is 1.0 mol H2(g). What is the volume of the container? (Don't be surprised at the large size of the volume)
Wed Nov 16, 2016 9:17 pm
Forum: *Molecular Orbital Theory (Bond Order, Diamagnetism, Paramagnetism)
Topic: Why is He2 not a stable molecule?
Replies: 1
Views: 545

### Why is He2 not a stable molecule?

Is it because there are as many bonding as antibonding and then they cancel out and the bond order is 0? But then how come if the bond order is 0, that means the molecule is unstable?
Sat Nov 12, 2016 9:55 am
Forum: Octet Exceptions
Topic: Chapter 2 Quiz #7: Expanded Octets
Replies: 1
Views: 509

### Chapter 2 Quiz #7: Expanded Octets

Draw the Lewis structure for XeO2F2. Explain why this structure would be allowed for Xe as a central atom but not for Ne as a central atom.

I don't really understand how to answer part 2 of the question. Is it because Ne is too small or something?
Sat Nov 05, 2016 9:59 am
Forum: Sigma & Pi Bonds
Topic: Pi Bonds
Replies: 4
Views: 714

### Re: Pi Bonds

To answer your first question, yes pi bonds will always be in the p orbitals.
Sat Oct 29, 2016 9:11 pm
Forum: Electron Configurations for Multi-Electron Atoms
Replies: 3
Views: 568

### Re: Adding electrons for exceptions

I have the same question; it makes sense for Cu2+ but then for Cu2- you're adding two electrons, so would it go into the p orbital and be 3d10 4s2 4p1? Or is it even possible to have Cu2-?
Sun Oct 23, 2016 10:59 am
Forum: Naming
Topic: Naming for Quiz 2
Replies: 6
Views: 756

### Re: Naming for Quiz 2

Based on the Quiz 2 preparation quiz in the workbook, you don't need to know the polyatomic ions or they're given to you. Though I'd say it's good to know some of the frequently used polyatomic ions like sulfate, just in case.
Sat Oct 15, 2016 2:06 pm
Forum: Ionic & Covalent Bonds
Topic: Ionization Energy
Replies: 7
Views: 890

### Re: Ionization Energy

Also, I remember in class Dr. Lavelle said hydrogen is never in the center.
Fri Oct 07, 2016 4:21 pm
Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
Topic: Fall 2014 Quiz Prep
Replies: 11
Views: 1114

### Re: Fall 2014 Quiz Prep

I put n=4 into n-initial and solved for n-final which allowed me to get n=6. I'm wondering why this worked because the problem asked for the quantum level where the electron began. You got the same answer cause you did +deltaE=initial-final, and the actual way is -deltaE=final-initial. Delta E is n...
Fri Oct 07, 2016 3:36 pm
Forum: Heisenberg Indeterminacy (Uncertainty) Equation
Topic: Quiz Preparation #5 [ENDORSED]
Replies: 1
Views: 438

### Re: Quiz Preparation #5[ENDORSED]

Delta v would be 2 times .1 which is .2, since .1 is the uncertainty in the velocity and the value of v can range from 2.25 to 2.45. You can also think of delta v as 2.45-2.25, which is .2. Hope this helps!
Fri Sep 30, 2016 1:24 pm
Forum: Properties of Light
Topic: Increasing Intensity in Photoelectric Effect [ENDORSED]
Replies: 9
Views: 1262

### Re: Increasing Intensity in Photoelectric Effect[ENDORSED]

Going off of this, he also mentioned threshold value a few times. Is that the value that the wavelength has to be shortened to in order for increasing intensity to actually remove electrons?