Search found 21 matches

by Arielle Kunitz 3A
Wed Mar 09, 2016 8:26 pm
Forum: *Alkenes
Topic: 2011 Final Exam Q7B
Replies: 1
Views: 330

2011 Final Exam Q7B

This problem is on pg 183 in the course reader in the practice final exam section; question 7 part b of 2011 final exam.

Could someone explain to me why it is ...pent-2-enoic acid? where does the 2 come from? I'm totally lost and would really appreciate some help!
by Arielle Kunitz 3A
Mon Mar 07, 2016 11:16 am
Forum: *Ethers
Topic: Ether/Ester mix up
Replies: 1
Views: 615

Re: Ether/Ester mix up

Here is a great website that simply clarifies the difference between Ethers and Esters: http://www.differencebetween.com/difference-between-ester-and-vs-ether/ This article states that esters don't have the capability to form strong H-bonds due to lack of hydrogen bounded to oxygen. So to answer you...
by Arielle Kunitz 3A
Sun Feb 28, 2016 10:23 pm
Forum: *Alkanes
Topic: Naming of Organic Compounds
Replies: 1
Views: 320

Re: Naming of Organic Compounds

I believe so, even though it wasn't heavily emphasized in lectures. However, Dr. Casey brought up the use of parentheses when a substituent has a substituent (eg4-methyl-5(2-methyl-propyl)-nonane. As for dashes, I'm not quite sure what the absolute rule is. The course reader seems to put a dash betw...
by Arielle Kunitz 3A
Mon Feb 22, 2016 10:16 am
Forum: *Electrophiles
Topic: Memory Tips
Replies: 8
Views: 1143

Re: Memory Tips

Also, if you remember that nucleophiles ATTACK electrophiles, you can think of attacking being a negative action. nucleophiles are electron dense, meaning that they have a high negative charge. so you can think of them being pessimistic! haha hope this helps :)
by Arielle Kunitz 3A
Mon Feb 15, 2016 2:20 pm
Forum: General Rate Laws
Topic: Including k in rate laws
Replies: 4
Views: 598

Re: Including k in rate laws

I believe you will have to solve for k, but maybe this depends on the problem. For example, on page 62 of the course reader, it says calculate k at any concentration. So, I believe you do have to solve for k.
by Arielle Kunitz 3A
Sun Jan 31, 2016 11:32 am
Forum: Gibbs Free Energy Concepts and Calculations
Topic: Free energy terms
Replies: 1
Views: 205

Re: Free energy terms

In general, whenever you see X o , that means under standard conditions (H o , S o , G o ) So, \Delta G^{o} is the standard free energy under standard conditions (1 atm, 1M, etc) at equilibrium (where the number of moles of reactants equal the moles of products) From this, we can see that there is a...
by Arielle Kunitz 3A
Sun Jan 24, 2016 12:48 pm
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: HW 8.49
Replies: 2
Views: 357

HW 8.49

The problem states: "Oxygen difluoride is a colorless, very poisonous gas that reacts rapidly with water vapor to produce O2, HF, and heat: OF2(g) + H20(g) yields O2(g) + 2HF(g) where deltaH = -318kJ What is the change in internal energy for the reaction of 1.00 mol OF2?" I noticed in the ...
by Arielle Kunitz 3A
Sun Jan 24, 2016 12:32 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Question 8.45 C
Replies: 1
Views: 287

Re: Question 8.45 C

No, this is not an error. The equation you should use to set it up is q=deltaH=n CS2 (358kJ/mol)/4 mol CS 2 then you plug in 415kJ/mol for deltaH: 415kj/mol=n CS2 (358kJ/mol)/4 mol CS 2 solving for n CS2 : n CS2 =415kJ/mol(4 mol CS 2 )/(358.8kJ/mol) the units cancel, leaving n CS2 =4.63 mol Hope thi...
by Arielle Kunitz 3A
Sun Jan 24, 2016 12:19 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Typo in question 8.55?
Replies: 2
Views: 436

Re: Typo in question 8.55?

Don't worry about it--Lavelle said to skip #55 :)
by Arielle Kunitz 3A
Fri Jan 15, 2016 5:20 pm
Forum: Thermodynamic Definitions (isochoric/isometric, isothermal, isobaric)
Topic: Clairifcation on when to use entropy equations.
Replies: 3
Views: 691

Re: Clairifcation on when to use entropy equations.

My understanding is that when you are given moles of gas, use the nRln(V2/V1) equation; otherwise, use the kBln(W2/W1) equation.
by Arielle Kunitz 3A
Sun Jan 10, 2016 7:21 pm
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: Molar heat capacity
Replies: 1
Views: 280

Re: Molar heat capacity

The heat capacity at constant volume of a gas is (dU/dT)V= cv

The heat capacity at constant pressure of a gas is (dU/dT)V= cp=cv+R


Hope this helps!
by Arielle Kunitz 3A
Sat Dec 05, 2015 10:53 pm
Forum: *Molecular Orbital Theory Applied To Transition Metals
Topic: Deciding to use less than 8 or more than 8 MO Diagram
Replies: 2
Views: 1019

Deciding to use less than 8 or more than 8 MO Diagram

If we are asked to draw a MO diagram for something like NO or CO (where one atom is less than 8 and one is more than 8), do you draw the diagram for less than 8 (with the pi orbitals below the sigma orbitals) or the way for more than 8?
Thanks so much!
by Arielle Kunitz 3A
Sat Dec 05, 2015 3:02 pm
Forum: *Making Buffers & Calculating Buffer pH (Henderson-Hasselbalch Equation)
Topic: Fall 2011 Final Exam Q7A
Replies: 1
Views: 438

Fall 2011 Final Exam Q7A

The problem asks: which base and its conjugate acid would you choose as optimal for making the buffer and why? I understand that an optimal buffer has a pH close to the pKa, so does that also mean that the pOH is close to the pKb? That was the way that I solved the problem (pOH rather than pH), sinc...
by Arielle Kunitz 3A
Sun Nov 29, 2015 11:54 pm
Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
Topic: Negative pH???
Replies: 2
Views: 461

Negative pH???

I remember in lecture that the pH can be below zero or above 14. Could somebody explain how this could happen?
Thanks so much!
by Arielle Kunitz 3A
Sun Nov 22, 2015 11:13 pm
Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
Topic: Video explaining deprotonization and pH of acids
Replies: 4
Views: 642

Re: Video explaining deprotonization and pH of acids

Thanks for the video, this really helped soldify multiple concepts for me. However, I'm still slightly lost on a few ideas. Could you further explain the difference between Ka and Kb, and when you would use one over the other? Also, how does the 5% rule play a part in the example of a weak acid? Tha...
by Arielle Kunitz 3A
Tue Nov 10, 2015 4:21 pm
Forum: Naming
Topic: HW 17.31 part d
Replies: 2
Views: 391

HW 17.31 part d

This question states to write the formula for sodium bisoxalato(diaqua)ferrate(III).
Would it be incorrect to write diaqua as (H2O)2 rather than (OH2)2?

The solutions manual liss it as (OH2)2 for part d but as (H2O)2 for part c...

Thanks!
by Arielle Kunitz 3A
Sun Nov 01, 2015 8:50 pm
Forum: Hybridization
Topic: S-character of a hybrid orbital
Replies: 2
Views: 3437

Re: S-character of a hybrid orbital

I think of it like the ratio of S to other hybrid orbitals (P and/or D) SP hybridization has a 1:1 ratio SP2 has a 1:2 ratio SP3D2 has a 1:5 ratio The 1:1 SP will have the most S-character This yield as larger bond angle (180 degrees, linear in shape) than, let's say, SP3D2 (90 degrees, octahedral i...
by Arielle Kunitz 3A
Tue Oct 20, 2015 11:30 pm
Forum: Electronegativity
Topic: Which element is more electronegative?
Replies: 1
Views: 863

Which element is more electronegative?

Would Oxygen or Chlorine be considered more electronegative? I understand that the trend states that as you move up and across, from left to right, the periodic table, the more electronegative the element is, with Fluorine being the most electronegative. However, Oxygen is directly to the left and C...
by Arielle Kunitz 3A
Sun Oct 18, 2015 8:10 pm
Forum: Lewis Structures
Topic: Glycine Lewis Structure
Replies: 1
Views: 805

Glycine Lewis Structure

3.41c: Write the complete Lewis Structure of each of the following compounds: glycine, H2C(NH2)COOH, the simplest of amino acids the building blocks of proteins. Is the arrangement of the Lewis Structure that is found in the solutions manual the only possible structure for glycine, or does this have...
by Arielle Kunitz 3A
Wed Oct 14, 2015 8:09 pm
Forum: Trends in The Periodic Table
Topic: Initial Period Table
Replies: 1
Views: 369

Initial Period Table

Out of curiosity...
Were any elements misplaced initially on the first periodic table, when categorized solely by their physical properties?
If so...why did they not follow the trend?
Much appreciated,
Arielle Kunitz
by Arielle Kunitz 3A
Mon Sep 28, 2015 9:14 pm
Forum: Administrative Questions and Class Announcements
Topic: Materials for Discussion Sections
Replies: 1
Views: 341

Materials for Discussion Sections

What materials are recommended to bring to discussion? Specifically, is it necessary to bring the textbook, or will the course reader suffice?
Thank you!

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