Search found 37 matches

by Camryn Marshall 1C
Tue Mar 08, 2016 8:15 pm
Forum: *Aldehydes
Topic: Aldehyde Numbering
Replies: 1
Views: 525

Aldehyde Numbering

In the O-chem book it says that because the aldehyde is always on the first carbon, numbering isnt necessary. For example, propanal would not be propan-1-al. However if we put the second one on a test just to be safe would that be counted as wrong?
by Camryn Marshall 1C
Sun Mar 06, 2016 9:29 pm
Forum: *Alkanes and Substituted Alkanes (Staggered, Eclipsed, Gauche, Anti, Newman Projections)
Topic: How can you tell if a molecule is cis (Z) or trans (E)?
Replies: 3
Views: 536

Re: How can you tell if a molecule is cis (Z) or trans (E)?

I went to an office hours where the TA said that Cis and Z/ Trans and Z are not the same thing. If thats the case I dont understand the difference because in most examples that weve done theyve seemed pretty interchangeable.
by Camryn Marshall 1C
Sun Feb 28, 2016 9:26 pm
Forum: *Organic Reaction Mechanisms in General
Topic: R and S Isomers
Replies: 1
Views: 259

R and S Isomers

the Organic Chemistry book talks about R and S isomers in chapter 4.3 but it says to see section 3.5 about the R and S system but we didnt cover that chapter. should we still know about them?
by Camryn Marshall 1C
Fri Feb 26, 2016 9:41 am
Forum: *Nucleophilic Substitution
Topic: Transition states
Replies: 1
Views: 322

Transition states

In SN2 if you are writing the rare laws (not the overall reaction) would you include the transition states for example when carbon has 5 bonds, in the rate law?
by Camryn Marshall 1C
Tue Feb 23, 2016 5:34 pm
Forum: *Free Energy of Activation vs Activation Energy
Topic: 4.30
Replies: 1
Views: 271

4.30

The question says: the activation energy in an organic reaction is 125 kj.mol. Will this reaction occur at room temperature?
How do I solve this?
by Camryn Marshall 1C
Fri Feb 19, 2016 9:09 pm
Forum: Arrhenius Equation, Activation Energies, Catalysts
Topic: Structure for the activated complex (HW 15.85)
Replies: 3
Views: 564

Re: Structure for the activated complex (HW 15.85)

Why for b) would it be termoleuclar? That is what the solutions manual says
by Camryn Marshall 1C
Fri Feb 19, 2016 9:52 am
Forum: Arrhenius Equation, Activation Energies, Catalysts
Topic: 15.65
Replies: 1
Views: 252

15.65

This question gives that k= 265 L.mol.min and the EA= 39.7x103 and k'= 392 L.mol.min and EA'= 25.4x103. It asks if this reaction is endothermic or exothermic. I would think that it would be exothermic because k<k' but the solutions manual says that it's endothermic because the reverse reaction has a...
by Camryn Marshall 1C
Sat Feb 13, 2016 5:52 pm
Forum: Administrative Questions and Class Announcements
Topic: Quiz 2 Winter 2016
Replies: 18
Views: 6974

Re: Quiz 2 Winter 2016

Question 61 deals with activation energies so I think we stop there so the last problem we should be able to do on the homework for Quiz 2 would be 55
by Camryn Marshall 1C
Fri Feb 12, 2016 11:47 am
Forum: Reaction Mechanisms, Reaction Profiles
Topic: Temperature and reaction rate
Replies: 1
Views: 280

Temperature and reaction rate

In lecture, professor Lavelle said that from experience cooling slows reactions like when you put food in the fridge. Why then does food not spoil when heating it up or cooking it because temperature would then increase the reaction?
by Camryn Marshall 1C
Mon Feb 08, 2016 12:32 am
Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
Topic: 2014 Midterm #8
Replies: 4
Views: 584

Re: 2014 Midterm #8

Also for this problem i was wondering how you know to take the square root of K to get Ka/ what does Ka represent or mean?
by Camryn Marshall 1C
Sun Feb 07, 2016 11:10 pm
Forum: Concepts & Calculations Using Second Law of Thermodynamics
Topic: delta S surroundings =0
Replies: 1
Views: 231

delta S surroundings =0

Conceptually, why is delta S for the surroundings =0 for irreversible reactions?
by Camryn Marshall 1C
Fri Feb 05, 2016 6:23 pm
Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
Topic: 14.37
Replies: 1
Views: 264

14.37

For this problem, it asks to find the potential for the cells given. I am confused how to calculate E when the abbreviated cell diagrams have pressures and moles in them. For example, part b reads Zn(s)| Zn2+(aq, .37 mol.L)|| Ni2+ (aq, .059 mol.L)| H2 (g, 1 bar)| Pt(s) I know how to find Eo for the ...
by Camryn Marshall 1C
Fri Feb 05, 2016 6:17 pm
Forum: First Order Reactions
Topic: Derivations
Replies: 1
Views: 300

Derivations

So for the quiz, we had to know the derivation of entropy and I was wondering if I should know the derivation of first order and second order reactions.
by Camryn Marshall 1C
Sun Jan 31, 2016 3:06 pm
Forum: Balancing Redox Reactions
Topic: Oxidation vs Reduction
Replies: 2
Views: 544

Oxidation vs Reduction

this may be a dumb question but I am still really confused how to tell in general which is reduced or oxidized. I start to think that I get it and whenever I answer one of the questions I always get the atom/ molecule that oxidized and reduced mixed up. Is there a trick to knowing which one is which?
by Camryn Marshall 1C
Fri Jan 22, 2016 11:00 pm
Forum: Concepts & Calculations Using Second Law of Thermodynamics
Topic: Reversible vs Irreverible reactions
Replies: 1
Views: 190

Reversible vs Irreverible reactions

I'm still so confused what the difference between reversible and irreversible reactions are and what they mean and how you can tell if a reaction is reversible.
by Camryn Marshall 1C
Thu Jan 21, 2016 12:42 am
Forum: Concepts & Calculations Using First Law of Thermodynamics
Topic: Problems with formulas
Replies: 1
Views: 272

Problems with formulas

As Im going through the problems Im having trouble knowing when to use certain formulas or when to use certain constants for R and I was wondering if someone could help with this problem somehow? Should I just memorize when to use certain formulas and certain constants? -Also in the solutions manual...
by Camryn Marshall 1C
Thu Jan 21, 2016 12:37 am
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: 3/2 and 5/2 R
Replies: 5
Views: 1526

Re: 3/2 and 5/2 R

How would we have known this without seeing it in the solutions manual? Is it listed somewhere in the textbook?
by Camryn Marshall 1C
Sun Jan 17, 2016 11:06 pm
Forum: Entropy Changes Due to Changes in Volume and Temperature
Topic: General Confusion with mictrostates and bulk property
Replies: 1
Views: 287

General Confusion with mictrostates and bulk property

In lecture Professor Lavelle gave and example in the course reader with a diagram that shows a vacuum and an ideal gas with a mass that decreases slowly. Im confused on this whole concept and i was wondering if someone could explain it to me. I understand the equations and the concepts but I dont un...
by Camryn Marshall 1C
Tue Jan 05, 2016 7:33 pm
Forum: Phase Changes & Related Calculations
Topic: Hm
Replies: 1
Views: 328

Hm

Today in disucssion our TA went over phase changes for Enthalpy for example the change in H for vamporization = Hm(vapor)-Hm(liquid) and the reaction is endothermic. I was wondering if someone can explain to me what Hm is?
by Camryn Marshall 1C
Thu Dec 03, 2015 9:51 pm
Forum: *Titrations & Titration Calculations
Topic: 12.23
Replies: 11
Views: 1580

Re: 12.23

Im still a little confused on what you did to find the final pH..
what would be the chemical equation and also i know that sometimes you have to subtract moles added to find the moles left over? the two may be completely unrelated but im still confused
by Camryn Marshall 1C
Thu Dec 03, 2015 9:21 pm
Forum: *Titrations & Titration Calculations
Topic: HW 13.23
Replies: 3
Views: 438

Re: HW 13.23

You can calculate the volume because you know that at the stoichiometric point moles of sample is equal to the moles added so since you know molarity of the substance added you can do V=n/M for the substance added
by Camryn Marshall 1C
Thu Dec 03, 2015 9:18 pm
Forum: *Titrations & Titration Calculations
Topic: Chapter 13, Q23
Replies: 1
Views: 322

Re: Chapter 13, Q23

At the stoichiometric point in the titration, the moles of sample are equal to the moles added. So if you know the molarity of the added substance and now you know the moles than you can divide n/M to find the volume.
by Camryn Marshall 1C
Sun Nov 29, 2015 4:08 pm
Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
Topic: Dissociation Reactions in Water
Replies: 1
Views: 301

Dissociation Reactions in Water

Some of the problems ive come across in the homework say to calculate the pH of various molecules (ex. AlCl3 or Cu(NO3)2). How would you write the dissociation reaction for each of these? For example in the solutions manual, AlCl3 is written as Al(H2O)6 3+ + H20 <-> H30+ + Al(H20)5OH2+ I was wonderi...
by Camryn Marshall 1C
Sun Nov 29, 2015 2:55 pm
Forum: Photoelectric Effect
Topic: Video: Photoelectric Effect Example
Replies: 3
Views: 499

Re: Video: Photoelectric Effect Example

what do you mean post in a different format?
by Camryn Marshall 1C
Sun Nov 29, 2015 2:52 pm
Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
Topic: determining acid/ base
Replies: 1
Views: 258

determining acid/ base

In general, how can you tell just by looking at a molecule if it is an acid or a base? I am confused on the concepts involved in acids and bases so i was also wondering if there is another resource i can go to to just get general help with concepts instead of specific help with questions.
by Camryn Marshall 1C
Sun Nov 29, 2015 2:36 pm
Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
Topic: 12.63 Concepts
Replies: 1
Views: 447

12.63 Concepts

just in general im really confused on the concepts of acids and bases in terms of Ka Kb and Kw vs. pka and pkb so for this problem could someone explain how to do it conceptually? "The percentage deprotonation of benzoic acid in a 0.110 M solution is 2.4%. What is the pH of the solution and the...
by Camryn Marshall 1C
Fri Nov 27, 2015 11:26 pm
Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
Topic: Determining pH
Replies: 3
Views: 608

Re: Determining pH

can you explain how to find [H30+] using an ice box?
by Camryn Marshall 1C
Wed Nov 25, 2015 6:05 pm
Forum: Photoelectric Effect
Topic: Video: Photoelectric Effect Example
Replies: 3
Views: 499

Video: Photoelectric Effect Example

Number 3 on Fall Midterm 2015
by Camryn Marshall 1C
Mon Nov 16, 2015 10:36 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: 11.67 Why do we use a new initial value?
Replies: 4
Views: 306

Re: hw problem 11.67

i think they are referring to the solutions manual for this question. In the ICE box there is an initial and a new initial. Um im not sure why that is I asked my TA and she doesnt even know so I think you can solve the problem without doing it that way
by Camryn Marshall 1C
Fri Nov 13, 2015 4:24 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Solving Quadratic Equations
Replies: 1
Views: 170

Solving Quadratic Equations

Is there an easier way to solve the chemical equilibrium problems than by using the quadratic formula because with all the decimals and weird numbers its easy to make mistakes especially when using a scientific calculator. Thanks!
by Camryn Marshall 1C
Mon Nov 02, 2015 4:19 pm
Forum: *Molecular Orbital Theory (Bond Order, Diamagnetism, Paramagnetism)
Topic: Bonding vs Antibonding
Replies: 2
Views: 388

Bonding vs Antibonding

Im lost on the whole concept of bonding vs antibonding. I understand in terms of molecular orbital theory because I can memorize how the diagram should look but besides that I dont understand it conceptually. For example on number 77 of the homework it says draw the bonding and antibonding orbitals ...
by Camryn Marshall 1C
Sat Oct 10, 2015 2:10 pm
Forum: Trends in The Periodic Table
Topic: Ionization energy for oxygen hw 2.81
Replies: 3
Views: 495

Re: Ionization energy for oxygen hw 2.81

Oxygen has lower ionization energy than Nitrogen because of the repulsion of electrons. The presence of more electron means that electrons shield the outer electrons from the protons. -wouldnt this mean though that ionization energy would decrease across a period then because each element is adding...
by Camryn Marshall 1C
Sat Oct 10, 2015 2:02 pm
Forum: Trends in The Periodic Table
Topic: Electron affinity trends
Replies: 2
Views: 560

Electron affinity trends

Is there a trend that shows increasing and decreasing electron affinity on the periodic table? If not how would we be able to calculate the electron affinity?
by Camryn Marshall 1C
Sat Oct 10, 2015 1:36 pm
Forum: Quantum Numbers and The H-Atom
Topic: Chapter 2 question 85
Replies: 1
Views: 293

Chapter 2 question 85

"In heavier transition metal elements, especially the lanthanoids and actinoids, there are numerous exceptions to the regular order of orbital occupation predicted by the building up principle.l Suggest why more exceptions would be noted for these elements"
Will someone explain this to me?
by Camryn Marshall 1C
Tue Oct 06, 2015 3:51 pm
Forum: Properties of Light
Topic: HW 1.57 Balmer series
Replies: 3
Views: 578

HW 1.57 Balmer series

The question says "Lines in the Balmer series of the hydrogen spectrum are observed at 656.3, 486.1, 434.0 and 410.2. What is the wavelength of the next series?" So I did the problem and then I looked in the solutions manual and it says that "since the Balmer series n1= 2, the fifth l...
by Camryn Marshall 1C
Sun Oct 04, 2015 3:33 pm
Forum: Heisenberg Indeterminacy (Uncertainty) Equation
Topic: Homework 1.43
Replies: 4
Views: 549

Homework 1.43

For question 43, it asks what is the minimum uncertainty in the speed of an electron confined to within a lead atom of diameter 350pm. Also it asks to model the atom as a one dimensional box w length equal to diameter of the actual atom. I looked up the equation and i found it but we haven't learned...
by Camryn Marshall 1C
Tue Sep 29, 2015 10:36 am
Forum: Properties of Light
Topic: Question on photoelectric effect experiement
Replies: 2
Views: 328

Question on photoelectric effect experiement

In the photoelectric effect experiment discussed in the last lecture, why didnt increasing the intensity of the first light source increase the number of photons like it did when they changed to a different light source with a higher frequency. I know that increasing the intensity of the light sourc...

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