Search found 12 matches

by Cris Yuan 2I
Sat Mar 18, 2017 4:05 pm
Forum: Administrative Questions and Class Announcements
Topic: Ashley Sarquiz Award Winter 2017
Replies: 2
Views: 729

Re: Ashley Sarquiz Award Winter 2017

Congratulations to Ashley!
by Cris Yuan 2I
Mon Mar 13, 2017 12:35 am
Forum: Administrative Questions and Class Announcements
Topic: Excellence in Chemistry Award 2015-16
Replies: 6
Views: 853

Re: Excellence in Chemistry Award 2015-16

Here're two pictures from the sides:
IMG_1919.JPG
by Cris Yuan 2I
Sun Mar 12, 2017 2:43 pm
Forum: Student Social/Study Group
Topic: Post All Chemistry Jokes Here
Replies: 7581
Views: 1013908

Re: Post All Chemistry Jokes Here

Here's a fun one about hydrocarbons:
putan-puten-putin-chemical-bond-formula.jpg
by Cris Yuan 2I
Mon Mar 06, 2017 11:27 pm
Forum: *Organic Reaction Mechanisms in General
Topic: Pseudo-equilibrium constant
Replies: 1
Views: 296

Re: Pseudo-equilibrium constant

If you look at reader p86, it states that the pseudo-equilibrium constant allows us to relate the concentration of the activated complex to the concentrations of the reactants. I think we could use the concentration of the reactants to find out the concentration of the activated complex in problems,...
by Cris Yuan 2I
Mon Mar 06, 2017 11:15 pm
Forum: *Electrophilic Addition
Topic: Final Winter 2014 #5B
Replies: 1
Views: 488

Re: Final Winter 2014 #5B

You could see from the diagram that the double bond becomes a single bond, so one of the Cs has received an H+ and the other a Br-. Since the second C received the Br, the H+ most likely goes to the C on the left, which is technically the third carbon because functional group comes first. Br | CH2=C...
by Cris Yuan 2I
Sun Mar 05, 2017 1:32 pm
Forum: *Electrophiles
Topic: CH3Cl
Replies: 2
Views: 691

Re: CH3Cl

I think page 82 of the reader explains CH3Cl and other alkyl halides very well:
The C is the electron deficient electrophile site, and because Cl is the nucleophile site, the C-Cl bond could quickly donate an electron to Cl when it attracts a nucleophile.
by Cris Yuan 2I
Sun Mar 05, 2017 1:16 pm
Forum: *Free Energy of Activation vs Activation Energy
Topic: exergonic vs exothermic
Replies: 2
Views: 652

Re: exergonic vs exothermic

For your second question, since ΔG=ΔH-TΔS, an exothermic reaction means ΔH<0, so unless ΔS<0 AND the reaction is at a very high temperature, the reaction will probably be exergonic as well. When a reaction is exergonic, ΔG<0, so unless ΔS>0 AND the reaction is at a very high temperature, the reactio...
by Cris Yuan 2I
Sun Feb 26, 2017 12:36 am
Forum: Arrhenius Equation, Activation Energies, Catalysts
Topic: Ch.15 question 15.85
Replies: 2
Views: 263

Re: Ch.15 question 15.85

The activation complex theory is just the transition state theory that we've learned in class, so you would refer to Reader page 85 about understanding and drawing one. It is a state that has partially formed bonds, while intermediates have fully formed bonds. so since it is a transition state, the ...
by Cris Yuan 2I
Sat Feb 25, 2017 11:59 am
Forum: Arrhenius Equation, Activation Energies, Catalysts
Topic: Catalysts and equilibrium constant
Replies: 4
Views: 393

Re: Catalysts and equilibrium constant

Since catalysts speed up forward and reverse reactions to the same extent, the addition of a catalyst should not affect equilibrium constant.
by Cris Yuan 2I
Sat Feb 25, 2017 11:54 am
Forum: Arrhenius Equation, Activation Energies, Catalysts
Topic: What is the catalyst in this reaction? [ENDORSED]
Replies: 2
Views: 748

Re: What is the catalyst in this reaction? [ENDORSED]

For catalyst, you can look for something that does not appear in the net equation; in other words, it is not consumed nor produced in the reaction, so they are often used in the first step but produced in the second step. By the way, the intermediates are also absent from the net equation, but you c...
by Cris Yuan 2I
Sat Feb 25, 2017 12:00 am
Forum: Arrhenius Equation, Activation Energies, Catalysts
Topic: Quiz prep 2 #11
Replies: 4
Views: 528

Re: Quiz prep 2 #11

After you find the activation energy, plug in the value: ln(k)=-Ea/(R700K)+ln(A) and then use another equation: ln(35)=-Ea/(R350K)+ln(A) then subtract one from the other to get rid of A: ln(k/35)=-Ea/(R700K)+Ea/(R350K) k=35*e^(Ea(1/R350K-1/R700K) and plug in the value of Ea here, and the rest are pr...
by Cris Yuan 2I
Wed Jan 18, 2017 6:48 pm
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: 8.93 Textbook [ENDORSED]
Replies: 1
Views: 292

Re: 8.93 Textbook [ENDORSED]

A. I think it's the same as the problem Professor Lavelle talked about in class today. W=-pΔv=ΔnRT You would balance the equation and use the R for bar and T in Kelvin. B. You would calculate by reaction enthalpy, and the formula is in the reader and the textbook. C. ΔU= qp + w = enthalpy (from B) +...

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