## Search found 19 matches

Sun Mar 19, 2017 12:02 am
Forum: *Cyclopropanes and Cyclobutanes
Topic: energy barriers
Replies: 3
Views: 861

### Re: energy barriers

Michelle_Tan_1G wrote:Yes, any shift in conformation requires an energy collision with one of the structural atoms strong enough to overcome the energy barrier.

How are these energy barriers usually overcome? Also, are there any calculations associated with that?
Sat Mar 18, 2017 11:59 pm
Forum: *Cyclopropanes and Cyclobutanes
Topic: Finals
Replies: 2
Views: 819

### Re: Finals

Good Luck to you as well
Sat Mar 18, 2017 11:58 pm
Forum: *Calculations Using ΔG° = -RT ln K
Topic: Energy Calculations
Replies: 2
Views: 744

### Re: Energy Calculations

As Milan stated, it depends on the functional groups attached to the chair structure. With that being said, when those functional groups are farther from each other there is relatively less strain than if they were to be placed next to each other. Likewise, any axial positioning would create more st...
Fri Mar 17, 2017 11:02 pm
Forum: Reaction Mechanisms, Reaction Profiles
Topic: Pre-Equilibrium Approach ?
Replies: 1
Views: 386

### Pre-Equilibrium Approach ?

First of all, when would someone use this.
Secondly, When you get an expression such as $K=\frac{2k_{1}k_{2}}{k_{1}}$ how many values would we be given usually to solve for K ?
Fri Mar 17, 2017 8:03 pm
Forum: General Rate Laws
Topic: Catalysts in Rate Law
Replies: 1
Views: 388

### Re: Catalysts in Rate Law

If the catalyst is in the rate determining step then it is included in the rate law. If it cancels out (because it is a product and reactant) or is not in the rate determining step then it is not written in the rate law.
Fri Mar 17, 2017 7:53 pm
Forum: Administrative Questions and Class Announcements
Topic: Quiz 2 Winter 2017
Replies: 160
Views: 17494

### Re: Quiz 2 Winter 2017

Are the answers posted on Chem Community?
Fri Mar 17, 2017 7:44 pm
Forum: Method of Initial Rates (To Determine n and k)
Topic: Two Step Reactions
Replies: 3
Views: 556

### Re: Two Step Reactions

Yes, the slow step takes more energy to be carried out than the fast step. If you think about the 2 step free energy diagram that we did on Quiz 3, if k1 > k2 this means that the rate is faster for k1. If the rate is faster, the activation energy is lower (deltaGdoubledagger1). But k2 is slower, so...
Fri Mar 17, 2017 6:32 pm
Forum: Gibbs Free Energy Concepts and Calculations
Topic: Units for dG
Replies: 1
Views: 421

### Units for dG

If $\Delta H$ is kJ/mol and $\Delta S$ is usually given in J/mol, do we have to convert either value ( from kJ to mols vice versa) in order to get the correct value?
Also, what are the units for $\Delta G$?

Thanks !
Fri Mar 17, 2017 6:28 pm
Forum: *Alkanes
Topic: Organic molecule formulas
Replies: 2
Views: 898

### Re: Organic molecule formulas

I think it's pretty important to know the formulas and how to name the longest carbon chain based on that.
Fri Mar 17, 2017 6:04 pm
Forum: Gibbs Free Energy Concepts and Calculations
Topic: Winter 2016 Final Exam Q2A [ENDORSED]
Replies: 7
Views: 993

### Re: Winter 2016 Final Exam Q2A[ENDORSED]

I think you just work with the units you are given in the question.
Fri Mar 17, 2017 6:00 pm
Forum: Gibbs Free Energy Concepts and Calculations
Topic: 2016 Final
Replies: 3
Views: 614

### Re: 2016 Final

The overall pressure of the reactants is half the pressure of the product not that cl3 and cl2 are halves. So the denominator is still x^2 but the overall relationship between the reactants and products is that the reactants are half which I believe is why you would multiply by 2 instead of multiply...
Fri Mar 17, 2017 5:35 pm
Forum: Calculating Standard Reaction Entropies (e.g. , Using Standard Molar Entropies)
Topic: Bond Energies Final 2013 #1
Replies: 2
Views: 423

### Bond Energies Final 2013 #1

So even if h202 is being broken down into 02 and h20, are 02 and h20 considered reactants and thus negative in solving for dH?
Basically, how are reactants and products being determined here and how do we determine which set of bonds are positive and negative?
Sat Dec 05, 2015 11:20 pm
Forum: Ionic & Covalent Bonds
Topic: covalent character
Replies: 5
Views: 4346

### Re: covalent character

AgF is less covalent than Becl2 because Fluorine is the most electronegative element on the periodic table its most likely to just take the electron to get to the octet state rather than share which is what covalent bonding is.
Sat Dec 05, 2015 8:16 pm
Forum: *Titrations & Titration Calculations
Topic: Henderson Hasselbalch's equation
Replies: 2
Views: 526

### Re: Henderson Hasselbalch's equation

From my discussion notes if the Percent Dissociation is less than 5% then you can use it. Or you can use the equation whenever x is negligible (when is disappears).
Sat Dec 05, 2015 8:05 pm
Forum: Air Pollution & Acid Rain
Topic: Reducing Acid Rain
Replies: 4
Views: 1654

### Re: Reducing Acid Rain

I just found a study that says adding calcium to acid rain depleted forests will reverse the effects and actually make the forest healthier ! While yes the best ways to prevent it are using less energy and scrubbers, its cool to see how people are "fixing" the problems caused by acid rain....
Fri Dec 04, 2015 10:23 am
Forum: Naming
Topic: Is OH aqua or hydroxo?
Replies: 2
Views: 571

### Re: Is OH aqua or hydroxo?

Ah, Yes it is. Thanks!
Thu Dec 03, 2015 11:49 pm
Forum: Naming
Topic: Is OH aqua or hydroxo?
Replies: 2
Views: 571

### Is OH aqua or hydroxo?

In the course reader it says the name for Hydroxide ( $OH^-$ )is hydroxo but as noted on my quiz and on the 2010 final it is referred to as aqua ... Can someone clarify this discrepancy??
Tue Nov 03, 2015 4:27 pm
Forum: *Molecular Orbital Theory (Bond Order, Diamagnetism, Paramagnetism)
Topic: D-orbital in MO Diagram ...?
Replies: 1
Views: 513

### D-orbital in MO Diagram ...?

I was trying to do a Molecular Orbital Theory Diagram for Br_{2} and since the valence electron configuration is 3d^{10}4s^{2}4p^{5} I was wondering how we take into account the d orbital. I have googled and it seems like it is totally omitted in the diagram. If someone could explain how to do this ...
Fri Oct 02, 2015 10:51 am