Search found 34 matches

by Kayla_Black_2B
Thu Mar 16, 2017 1:11 pm
Forum: *Alkenes
Topic: Question 6 2016 winter final
Replies: 1
Views: 362

Re: Question 6 2016 winter final

I don't believe it would be incorrect, but I personally feel that is the easiest format to work with to ensure accuracy when a lot of substituents are involved. For example, in the ochem textbook, the solution for problem 1.12 part c provides possible answer choices in both formats (3,4,4-trimethyl-...
by Kayla_Black_2B
Thu Mar 16, 2017 1:06 pm
Forum: *Alcohols
Topic: Final 2015 - 9B
Replies: 2
Views: 539

Re: Final 2015 - 9B

Could you be referring to part A of problem 9? If so, I believe this is because as a functional group alcohol has first priority over substituents and cycloalkanes. Thus, in order to start numbering at the functional group, cycloheptane must be treated as a substituent to the 3rd carbon in the chain...
by Kayla_Black_2B
Wed Mar 15, 2017 9:46 pm
Forum: *Cyclopropanes and Cyclobutanes
Topic: Common Occurrence
Replies: 1
Views: 466

Re: Common Occurrence

I think it has something to do with the fact that they are not stable molecules, especially for cyclopropane because it has a large bond angle strain and torsional strain. Hope this helps! (Page 108 of course reader)
by Kayla_Black_2B
Wed Mar 15, 2017 9:35 pm
Forum: General Science Questions
Topic: Final
Replies: 9
Views: 1337

Re: Final

6... so I'm guessing like the midterm with multiple subquestions
by Kayla_Black_2B
Sun Mar 05, 2017 6:48 pm
Forum: *Cycloalkanes
Topic: Homework problem 1.16 cycloalkane naming
Replies: 3
Views: 321

Re: Homework problem 1.16 cycloalkane naming

Thanks! That was extremely helpful :)
by Kayla_Black_2B
Sun Mar 05, 2017 1:51 pm
Forum: Arrhenius Equation, Activation Energies, Catalysts
Topic: Section 4 question 30
Replies: 1
Views: 208

Re: Section 4 question 30

If I recall correctly, this may answer your question viewtopic.php?f=103&t=20159. I believe this is all in reference to the the standard Gibbs free energy equation for transition states on page 86 of the course reader. Hope this helps :)
by Kayla_Black_2B
Sun Mar 05, 2017 1:43 pm
Forum: *Cycloalkanes
Topic: Homework problem 1.16 cycloalkane naming
Replies: 3
Views: 321

Homework problem 1.16 cycloalkane naming

Hi, this might be asking a lot, but I was wondering if anyone can give me a step-by-step solution for naming the cycloalkane compound presented in problem 1.16. I'm not really sure how to name cycloalkanes with tons of substituents. Specifically, I'm having troubles understanding where to start numb...
by Kayla_Black_2B
Tue Feb 28, 2017 7:22 pm
Forum: *Alkynes
Topic: Homework Problem 1.5 Part C Molecular Formula
Replies: 1
Views: 492

Homework Problem 1.5 Part C Molecular Formula

Hi, from the ochem textbook, part c of problem 1.5 asks the type and molecular formula of a given structure that is three horizontal lines with the outer lines being shorter than the middle. I am having trouble recognizing how C3H4 is the molecular formula for it. Also, is that a single bond combine...
by Kayla_Black_2B
Tue Feb 28, 2017 6:55 pm
Forum: Student Social/Study Group
Topic: Good Tutors?
Replies: 3
Views: 565

Re: Good Tutors?

I'm not sure of any private tutors, but it may not be too late to attend PLF sessions through AAP (Campbell Hall). If you're a part of AAP, it's worth seeing if you can still, perhaps, unofficially attend a session. I find the sessions very helpful :)
by Kayla_Black_2B
Fri Feb 24, 2017 11:45 pm
Forum: General Rate Laws
Topic: 15.5 Positive vs Negative
Replies: 2
Views: 308

Re: 15.5 Positive vs Negative

I'm not completely sure but I think the negative in the rate of decomposition for O2 (-d[O2]/dt) is in terms of the general reaction rate and merely indicates that the concentration of O2 is being used up. Since "reacts" already implies the negative (O2 concentration decreasing), I think ...
by Kayla_Black_2B
Fri Feb 24, 2017 11:04 pm
Forum: *Organic Reaction Mechanisms in General
Topic: Biological Example Clarification
Replies: 1
Views: 222

Re: Biological Example Clarification

I believe what makes it possible for this to happen is the presence of just one double bond in the structure. Because there is just one double bond, it is unique to this structure. The double bond (pi, in particular) acts as a nucleophile while the H+ acts as an electrophile here. Then, Br- is more ...
by Kayla_Black_2B
Thu Feb 23, 2017 7:53 pm
Forum: *Electrophiles
Topic: CO2
Replies: 5
Views: 1007

Re: CO2

^ I don't think so, just because sometimes electrophiles and nucleophiles can be neutral (it's just more rare). For example, on pg.81 of the course reader, AlCl3 is listed as an electrophile. More of this is discussed in section 4.1 of the organic textbook. However, I am also surprised C02 is an ele...
by Kayla_Black_2B
Thu Feb 23, 2017 7:44 pm
Forum: Arrhenius Equation, Activation Energies, Catalysts
Topic: Homework problem 15.71
Replies: 1
Views: 276

Homework problem 15.71

Question 71 of chapter 15 from the textbook involves lewis structure diagrams or else I would repost the entire problem here. So, the hydroxide ion in step 2 is recognized as the catalyst for this reaction. Do catalysts generally or always appear on the product side of reactions? And the middle step...
by Kayla_Black_2B
Thu Feb 23, 2017 6:41 pm
Forum: Arrhenius Equation, Activation Energies, Catalysts
Topic: 15.61
Replies: 3
Views: 358

Re: 15.61

Ahh, I posted too soon. It works with a common denominator (found this out here viewtopic.php?f=151&t=19676).
by Kayla_Black_2B
Thu Feb 23, 2017 6:39 pm
Forum: Arrhenius Equation, Activation Energies, Catalysts
Topic: 15.61
Replies: 3
Views: 358

Re: 15.61

Hmm... I have the same question. I got a different answer than the solutions manual by using (1/T1 - 1/T2). Are you sure both equations work? ^ Maybe I'm just calculating wrong... If anyone can figure out why the solutions manual used a different equation, I'd really like to know too!
by Kayla_Black_2B
Sat Feb 11, 2017 8:32 pm
Forum: Balancing Redox Reactions
Topic: Recognizing which is the cathode and anode of Galvanic cell redox reactions
Replies: 1
Views: 198

Recognizing which is the cathode and anode of Galvanic cell redox reactions

Hi, my general question arises from problem 3B of the Winter 2016 Final. The question provides the two half reactions Al3+ +3e- --> Al(s) and Mg2+ + 2e- --> Mg(s) However, given the fact that both half reactions are written with electrons on the left hand side of the reaction, I'm unsure of how to t...
by Kayla_Black_2B
Mon Feb 06, 2017 6:55 pm
Forum: Gibbs Free Energy Concepts and Calculations
Topic: help understanding molar entropy [ENDORSED]
Replies: 1
Views: 367

help understanding molar entropy [ENDORSED]

The solutions manual for problem 9.55 of the homework states that there is a difference between the change in the standard entropy of formation (deltaSf) and molar entropy (Sm). The tables and appendices we use for the homework problems have only listed entropy values as molar entropy, so I'm curiou...
by Kayla_Black_2B
Tue Jan 31, 2017 7:58 pm
Forum: Concepts & Calculations Using Second Law of Thermodynamics
Topic: Homework Problem 9.15(b)
Replies: 2
Views: 336

Re: Homework Problem 9.15(b)

I got stumped on this problem until I realized I had accidentally used enthalpy of vaporization for water instead of the value for ethanol. Part b deals with a different compound than part a. You can find the enthalpy of vaporization in table 8.31!
by Kayla_Black_2B
Tue Jan 31, 2017 7:55 pm
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: HW problem 9.7
Replies: 1
Views: 201

Re: HW problem 9.7

I believe so, and 3/2 x R for constant volume, part b of the problem. The equation the solution manual uses since the problem deals with constants is deltaS=Cln(T2/T1) and Cp and Cv respectively will be plugged in for C. Hope this helps!
by Kayla_Black_2B
Tue Jan 31, 2017 7:50 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: Homework 9.21
Replies: 1
Views: 257

Homework 9.21

Hi, I realize that a few people have already asked questions regarding homework problem 9.21, but I have further questions about the problem. Is "Kb" Boltzmann's constant? If so, then is its value 1.3806x10^-23J/K? Thanks!
by Kayla_Black_2B
Tue Jan 24, 2017 8:35 pm
Forum: Phase Changes & Related Calculations
Topic: q=mC(delta)T vs. q=m(delta)Hvap
Replies: 1
Views: 1352

q=mC(delta)T vs. q=m(delta)Hvap

Hi, my question is more general in terms of when calculating the heat needed for a reaction, how does one know whether to apply the q=mC(delta)T formula or the q=m(delta)Hphasechange formula? Or both? For example, problem 8.87 of the textbook requires the usage of both equations and separate times i...
by Kayla_Black_2B
Tue Jan 24, 2017 8:25 pm
Forum: Student Social/Study Group
Topic: Quiz 1 Prep
Replies: 8
Views: 734

Re: Quiz 1 Prep

Would any of you be down Monday sometime in the evening or afternoon? Or is that too late? And somewhere on the hill might be nice!
by Kayla_Black_2B
Sun Jan 22, 2017 11:57 pm
Forum: Student Social/Study Group
Topic: Quiz 1 Prep
Replies: 8
Views: 734

Quiz 1 Prep

Anyone interested in studying the quiz 1 prep sometime together? Since there are no solutions manuals I would like to compare my answers with someone else's. Let me know if you're interested!
by Kayla_Black_2B
Sun Jan 15, 2017 2:27 pm
Forum: Thermodynamic Systems (Open, Closed, Isolated)
Topic: Ch 8. Q.1 [ENDORSED]
Replies: 2
Views: 345

Ch 8. Q.1 [ENDORSED]

Hi, I'm curious as to why d) gasoline burning in an automobile engine is an open system rather than closed? Since the engine is within the car, right?
by Kayla_Black_2B
Mon Nov 28, 2016 5:27 pm
Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
Topic: HW #12.69
Replies: 1
Views: 342

HW #12.69

I hope this questions hasn't already been asked, but I'm confused as to why Al3+ is written as Al(H20)6 3+ on the left hand side of the solution for the chemical reaction. Why is water being included with Al?

Thanks!
by Kayla_Black_2B
Wed Nov 23, 2016 11:30 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: When Should I use the ICE table?
Replies: 6
Views: 12913

Re: When Should I use the ICE table?

I think the purpose of using an ICE table is when one wants to know the concentrations of components in a reaction at equilibrium when only given limited data such as initial concentrations and the reaction equilibrium constant. By solving for how each concentration is changed in a reaction (ICE tab...
by Kayla_Black_2B
Mon Nov 14, 2016 6:52 pm
Forum: Administrative Questions and Class Announcements
Topic: 14B Enrollment
Replies: 1
Views: 498

Re: 14B Enrollment

I asked a couple of second years about what they would do in the instance that myself (or anyone else) is unable to enroll in 14B due to the limited seats.They mentioned that if enough people who do not get 14B express their concerns to the department that creates the schedule, they generally consid...
by Kayla_Black_2B
Tue Nov 08, 2016 4:12 pm
Forum: Naming
Topic: Aqua H20 or OH2?
Replies: 1
Views: 529

Aqua H20 or OH2?

Hi, I know someone briefly asked a question regarding this, but I'm curious as to why the solutions for problem 17.31 parts C&D alternate between listing aqua as (H20) and (OH2) since the convention seems to be H20. Is there much, if any, significance in the difference of H20 and OH2? If there i...
by Kayla_Black_2B
Sat Oct 29, 2016 5:57 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Chapter 4 Number 27
Replies: 2
Views: 268

Re: Chapter 4 Number 27

Hi, for part a of this question, the question mentions that pyridine has a structure similar to that of benzene except that a C-H group is replaced by Nitrogen. Since nitrogen has a larger electronegativity than that of carbon, its dipole moment causes the structure to be polar (and there's not anot...
by Kayla_Black_2B
Thu Oct 20, 2016 4:52 pm
Forum: Lewis Structures
Topic: Homework Question 3.27 Parts A&C [ENDORSED]
Replies: 1
Views: 272

Homework Question 3.27 Parts A&C [ENDORSED]

This question is probably more relevant to electron configuration, but I couldn't find an appropriate category to place it under. With parts A&C of this problem, I'm confused with what the relationship between the roman numerals in the name of the compound, the ionic charge, and the chemical for...
by Kayla_Black_2B
Fri Oct 14, 2016 10:42 am
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Homework Problem 2.39 Issue
Replies: 4
Views: 547

Re: Homework Problem 2.39 Issue

About nitrogen in this problem, I'm curious if it's even possible for one of the unpaired electrons to have an opposite spin to the other two unpaired electrons. Is this a violation of Hund's Rule?
by Kayla_Black_2B
Mon Oct 03, 2016 2:52 pm
Forum: Administrative Questions and Class Announcements
Topic: Even numbered textbook solutions?
Replies: 2
Views: 327

Even numbered textbook solutions?

Hi! Does anyone know if there's a list anywhere of solutions for the even numbered textbook problems? I haven't been able to find one in the book or online but maybe I'm just looking in the wrong places (or it doesn't exist anywhere). Thanks!
by Kayla_Black_2B
Mon Oct 03, 2016 2:46 pm
Forum: Student Social/Study Group
Topic: Sproul Hall Chem14A Study Group
Replies: 30
Views: 2273

Re: Sproul Hall Chem14A Study Group

I'm also in Sproul Hall and would like to join!
by Kayla_Black_2B
Wed Sep 28, 2016 11:18 pm
Forum: Empirical & Molecular Formulas
Topic: Order of writing ions in a molecule? [ENDORSED]
Replies: 3
Views: 504

Order of writing ions in a molecule? [ENDORSED]

Hi everyone, I'm posting because I'm curious as to how to determine the correct order for writing elements when calculating things such as the empirical&molecular formula. For example, would it be correct if I had a molecule containing carbon, hydrogen, and oxygen and I wrote it as CHO or HCO or...

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