## Search found 13 matches

Thu Mar 10, 2016 11:13 am
Forum: Student Social/Study Group
Topic: Post All Chemistry Jokes Here
Replies: 7951
Views: 1119815

### Re: Chemistry Jokes

Not exactly a chemistry joke, more like a pun.

It's the end of 14B and it's been a good run. Just wanted to say that we Lav-elle you, Professor :)
Thu Mar 03, 2016 11:09 am
Forum: *Constitutional and Geometric Isomers (cis, Z and trans, E)
Topic: Higher Priority
Replies: 2
Views: 3910

### Re: Higher Priority

CH3 because it has a higher molecular weight, I think.
Thu Feb 25, 2016 11:37 am
Forum: *Free Energy of Activation vs Activation Energy
Topic: Potential Energy vs Free Energy
Replies: 1
Views: 356

### Potential Energy vs Free Energy

On the homework we were asked to draw both a potential energy graph and a free energy graph (by this, I mean we used these as labels for the y-axis) for an organic reaction. I don't remember discussing potential energy of a reaction during lecture, is this something I might have just spaced out on o...
Thu Feb 18, 2016 11:11 am
Forum: Arrhenius Equation, Activation Energies, Catalysts
Topic: k in the Arrhenius Eq
Replies: 1
Views: 294

### Re: k in the Arrhenius Eq

The slope is negative for the line but it doesn't mean that the k value is negative. If the k value itself was negative, then in the integrated rate law equations for first and zeroth order, we would have a double negative, resulting in a positive slope. Like if k=-1 for a first order reaction, then...
Fri Feb 12, 2016 5:38 pm
Forum: General Rate Laws
Topic: Derivation of the Integrated Rate Law
Replies: 1
Views: 262

### Re: Derivation of the Integrated Rate Law

It doesn't matter too much in my opinion. We'd just derive each one the same way and more or less get the same equation, just differing by a constant. 1/a, 1/b, 1/c and so on are just constants, which can be "pulled out" during integration. I don't think there's any different equation we h...
Fri Feb 12, 2016 5:34 pm
Forum: General Rate Laws
Topic: Slow step vs fast step
Replies: 1
Views: 315

### Re: Slow step vs fast step

Don't take my word for it, but most likely it'll be given to us. That's what I've been seeing so far from all the homework problems.
Thu Feb 04, 2016 10:32 am
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Writing cell diagram: figuring out order
Replies: 2
Views: 317

### Re: Writing cell diagram: figuring out order

From what it seems to me, in the anode we usually write the (s) form first, before the (aq). I'm not 100% sure why, but it's just a general pattern I've been seeing while doing these problems. I'm also thinking because it acts as a conductor or some sort, like how we write Pt(s) first on the left-ha...
Thu Jan 28, 2016 8:03 pm
Forum: Gibbs Free Energy Concepts and Calculations
Topic: Two Gibbs Free Energy Formulas
Replies: 1
Views: 328

### Re: Two Gibbs Free Energy Formulas

I think the question will make it very obvious which equation you should use. If it mentions equilibrium or concentrations then most likely you'll use the one you mentioned. If it gives you information about enthalpy and entropy then use the deltaG = deltaH - TdeltaS.
Thu Jan 21, 2016 11:20 am
Forum: Concepts & Calculations Using Second Law of Thermodynamics
Topic: Entropy in irreversible processes
Replies: 1
Views: 220

### Entropy in irreversible processes

Hi everyone! As I was doing the homework (and checking the solutions manual at the same time), it seems like we use the deltaS = nR ln V2/V1 formula even for irreversible processes. I think it's problem 9.13 where I encountered this. Since we "derived" this formula assuming that it was a r...
Thu Jan 14, 2016 10:24 am
Forum: Thermodynamic Systems (Open, Closed, Isolated)
Topic: Heat given off by reaction
Replies: 1
Views: 784

### Re: Heat given off by reaction

Where is this example? Exothermic reactions have negative enthalpy by definition, don't they? I feel like either there's a mistake or you're misinterpreting this example. When heat is given off by the reaction, it's already implied that there is a negative energy change in the system because the ene...
Fri Jan 08, 2016 5:44 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Calculating Standard Reaction Enthalpy
Replies: 1
Views: 211

### Re: Calculating Standard Reaction Enthalpy

It's because the products are being formed, whereas the reactants are being broken apart in the reaction. Take the example from our course reader, CH4 + 2 O2 --> CO2 + 2 H2O. CH4 is being broken down in this reaction, instead of taking the standard enthalpy of formation of CH4, we take its negative ...
Mon Nov 23, 2015 7:26 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: Video: Le Chatelier's Principle and Equilibrium Calculations
Replies: 2
Views: 538

### Video: Le Chatelier's Principle and Equilibrium Calculations

Here is a video explaining problem 117 of chapter 17. We cover Le Chatelier's Principle and the ICE Box method of calculation.
Members of group: Raymond Le (3G), Trixie Le (3J), and Tram Vo (3J)

chem.wmv [ 274.56 MiB | Viewed 538 times ]

Fri Oct 09, 2015 10:22 pm
Forum: Ionic & Covalent Bonds