Search found 20 matches

by Gina_Chiarolla_3C
Sun Mar 19, 2017 12:32 am
Forum: *Cyclohexanes (Chair, Boat, Geometric Isomers)
Topic: Chair conformation
Replies: 3
Views: 873

Chair conformation

For a cyclohexane with an ethyl substituent, does it matter where you put the substituent to make it the most stable? Should it go on the tip? Or can you put it anywhere?
by Gina_Chiarolla_3C
Sun Mar 19, 2017 12:27 am
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Winter 2014 Final Q3
Replies: 1
Views: 307

Winter 2014 Final Q3

For part A, "Ash wants to supercharge his Pikachu for the upcoming Pokemon tournament. Use your knowledge of electrochemistry to help build a galvanic cell that can charge Pikachu!" How do you determine which substances to use?
by Gina_Chiarolla_3C
Sat Mar 18, 2017 12:25 am
Forum: *Cyclohexanes (Chair, Boat, Geometric Isomers)
Topic: Winter 2013 Final Question 8
Replies: 1
Views: 248

Winter 2013 Final Question 8

For part B, "Draw the most stale conformation for cis-1-chloro-3-ethylcyclohexane," do we have to draw the hydrogens in to receive full credit? Or can we simply draw the line structure with the 2 substituents?
by Gina_Chiarolla_3C
Sat Mar 18, 2017 12:22 am
Forum: Reaction Mechanisms, Reaction Profiles
Topic: Winter 2016 Final Question 4 [ENDORSED]
Replies: 2
Views: 614

Winter 2016 Final Question 4 [ENDORSED]

For this question, it ask "Which student mechanism is valid according to the experimentally determined rate law? Be sure to note which step must be the rate-limiting step for the mechanism to give the correct rate law." How exactly did they determine the second step rate laws for Students ...
by Gina_Chiarolla_3C
Sun Mar 05, 2017 4:27 pm
Forum: *Organic Reaction Mechanisms in General
Topic: Problem 28 Ch. 4
Replies: 2
Views: 338

Problem 28 Ch. 4

For problem 29, "Write the full reaction mechanism for the electrophilic addition reaction of hydrogen bromide, HBr, to propene, CH3CHCH2, producing 2-bromopropane, CH3CHBrCH3. Draw the transition states." How come after the first transition of electrons, the H from HBr attaches to the Car...
by Gina_Chiarolla_3C
Sat Mar 04, 2017 9:36 pm
Forum: *Nucleophilic Substitution
Topic: Naming with Substituents [ENDORSED]
Replies: 1
Views: 679

Naming with Substituents [ENDORSED]

How do you determine which substituent to start with while numbering. Is there a specific place to start the numbering?
by Gina_Chiarolla_3C
Sat Mar 04, 2017 9:34 pm
Forum: *Nucleophiles
Replies: 4
Views: 641


Why exactly is H2O a nucleophile?
by Gina_Chiarolla_3C
Fri Jan 27, 2017 8:05 pm
Forum: Thermodynamic Definitions (isochoric/isometric, isothermal, isobaric)
Topic: Derivations
Replies: 1
Views: 246


Do we have to be able to derive any of the equations on the quiz? We have gone through many derivations. I know we did not have to derive any equations in 14A but I have not heard anything about 14B.
by Gina_Chiarolla_3C
Tue Jan 24, 2017 7:34 pm
Forum: Calculating Work of Expansion
Topic: Quiz 1
Replies: 2
Views: 400

Quiz 1

For Quiz 1, what part of chapter 9 will be on the quiz? And will there be any review from chem 14A on the quiz? I have heard that there may be some but I don't know if the information is correct.
by Gina_Chiarolla_3C
Fri Jan 13, 2017 10:05 pm
Forum: Thermodynamic Systems (Open, Closed, Isolated)
Topic: Isolated Systems [ENDORSED]
Replies: 3
Views: 581

Isolated Systems [ENDORSED]

There is a question in the textbook that describes a high quality thermos as an isolated system. Why would this be considered an isolated system instead of a closed system if it is possible for the thermos to lose heat over long periods of time?
by Gina_Chiarolla_3C
Fri Dec 02, 2016 7:56 pm
Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
Topic: Equilibrium Equation
Replies: 1
Views: 277

Equilibrium Equation

On several homework problems, the molecule AlCl3 gets replaces with Al(H2O)6 in the equilibrium equation. Why does this happen?
by Gina_Chiarolla_3C
Tue Nov 22, 2016 11:23 pm
Forum: Properties & Structures of Inorganic & Organic Acids
Topic: Making Assumptions for weak acids
Replies: 1
Views: 300

Making Assumptions for weak acids

During Lecture, Lavelle talked about being able to make assumptions for weak acids. For example, when K(A)=1.8x10^-5. and K(A)=(X^2)/(.1-X), we can make the assumption that it's K(A)=(X^2)/(.1). Why can we do this?
by Gina_Chiarolla_3C
Mon Nov 14, 2016 6:39 pm
Forum: Administrative Questions and Class Announcements
Topic: 14B Enrollment
Replies: 1
Views: 570

14B Enrollment

For students who don't get into chem 14B, what course is recommended to take in its place? I am currently planning to take Math 3B but am not confident in getting into 14B as well.
by Gina_Chiarolla_3C
Wed Nov 09, 2016 2:15 pm
Forum: Naming
Topic: Charge on Compounds
Replies: 2
Views: 434

Charge on Compounds

For any given compound, how do we know if a molecule is neutral or if it contains a charge? Is this something we just need to know, like the fact that H2O molecules are neutral? Or is there a way to determine this?
by Gina_Chiarolla_3C
Sat Oct 29, 2016 1:21 pm
Forum: *Molecular Orbital Theory (Bond Order, Diamagnetism, Paramagnetism)
Topic: Midterm
Replies: 6
Views: 704


On Chemistry Community, it says the midterm covers all info through page 105 in the course reader, which does not include Molecular Orbital Energy Level Diagrams. But in previous midterms, they have questions that include these diagrams. Do we need to know how to produce these diagrams for the midte...
by Gina_Chiarolla_3C
Fri Oct 28, 2016 8:47 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Sigma/Pi Bonds
Replies: 1
Views: 340

Sigma/Pi Bonds

Can sigma bonds only be single bonds and pi bonds only be double bonds? And when is the bond both? I'm a little unclear on the topic.
by Gina_Chiarolla_3C
Fri Oct 21, 2016 1:10 pm
Forum: Lewis Structures
Topic: Lewis Structure for BF3
Replies: 1
Views: 953

Lewis Structure for BF3

In our course reader, there is the example of the Lewis structure for BF3 on page 85. The Lewis structure has three single bonds and three lone pairs around each F, creating 24 valence electrons. So, boron only has three bonds, not an octet. Why don't we remove one of the lone pairs and make a doubl...
by Gina_Chiarolla_3C
Sat Oct 15, 2016 4:55 pm
Forum: Resonance Structures
Topic: Breaking the Octet Rule
Replies: 6
Views: 1118

Breaking the Octet Rule

Are there any situations where the octet rule can be broken where an atom can contain less than 8 elections? Or does the atom have to satisfy the octet rule in all situations? I know there are exceptions for H, He, Li, and Be. But are there situations for any other elements?
by Gina_Chiarolla_3C
Fri Oct 07, 2016 5:18 pm
Forum: Significant Figures
Topic: When to Apply Sig Figs [ENDORSED]
Replies: 2
Views: 563

When to Apply Sig Figs [ENDORSED]

For all problems in general, should we be using the number of sig figs that the problem requires throughout the problem? Or should we be using all sig figs until the end of the problem and then a cut down or round to the correct about of sig figs at the end of the problem?
by Gina_Chiarolla_3C
Fri Sep 30, 2016 6:42 pm
Forum: General Science Questions
Topic: Atomic Spectra
Replies: 3
Views: 567

Atomic Spectra

For Question 1.15 on the homework: "In the ultraviolet spectrum of atomic hydrogen, a line is observed at 102.6 nm. Determine the values for n for the initial and final energy levels of the electron during the emission of energy that leads to this spectral line." Once you get to .889=(1/n1...

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