Pressure doesn’t affect the rate constant, right? If I have this reaction: 2A + B -> C + D (all gases), if I increase the pressure of the container, would I change the rate constant?
lol and we start again ^
@Mathman97 Yeah, thanks, just found it online. Didn’t think it was adding.
@glasshours It’s not adding them, if you want to take a look at the concept. 
GL tomorrow.
What is the difference between catalysts and intermediates when given fast and slow rate determining steps. Both cancel out so how do we find out?
@Mathman97 did you just completely ignore taw’s post…?
wait sippincoffee, you’re agreeing the sa, temp, pressure affects rate, yet it doesn’t affect k because it instead affects concentration then? i just want to make sure for tomorrow
is this what taw said?
C2H4 (g) + H2 (g) --> C2H6 (g)
in this reaction in which C2H4 is reduced in presence of a solid platinum catalyst, why does changing the partial pressure of H2 affect the reaction rate?
@jennyzh because changing pressure changes the speed which means rate changes
@Bodikbodik The catalyst will appear as a reactant in the first step and a product in the second step. An intermediate will appear as a product in the first step and a reactant in the second step. Hope that helps
increasing pressure would increase the rate of reaction. it would not change the reaction constant. instead it increases the contact of molecules, making reaction happens more frequently.
see my previous comment:
http://talk.collegeconfidential.com/discussion/comment/18448088/#Comment_18448088
if X were a gas and rate = k:
increasing pressure would increase the X rather than the k
CHANGING THE TOPIC
-Kc/Kp/Ka/Kwhatever is [products]/[reactants], but rate=k[reactants], right?
-Voltage is NOT affected by stoichiometric coefficients
-Positive delta S = increase in entropy (is this necessarily spontaneous?), negative delta G = spontaneous
ok got it!
thanks
yes
yes and yes, positive entropy is spontaneous, use G=h-TS to see if the other values correspond to sponteneity
-Correct
-correct
-correct
I think it’s thermodynamically favored when there’s more disorder and all that, but you mainly look at negative delta G
@glasshours Pretty much, negative delta G is a best indicator. Another indicator for spontaneity is a negative delta H. Still, always look for G first.
SIGH it’s tomorrow. I spent every day studying hours for ap chem and now the ap test is going to annihilate me.
do we need a pen for frq?
I got a 64 after taking the official 2014 practice test (which is just a modified 2014 test) and the official 2014 FRQs. 58 is where the 4s started using last year’s curve. Do I have a good chance of getting a 4 this year? I’m nervous about how I might have gotten lucky on some questions in both the FRQ and MC.