Official SAT Subject Test - Chemistry - June 2015

Everyone I know says that chemistry has a hard curve.

@blandscreenname yeah, it was the one with O2

Hmmm I remember it as O2 -> 2O. I even changed my answer from oxygen to hydrogen because of that.

@apactstudent Oh, did it say it was at a constant volume? I was thinking along the lines that energy cannot be created or destroyed, so the total energy in a system cannot increase.

Could anyone comment on the H2–>2H and 2O–>O2. people keep saying different things

I think the equation was making oxygen gas.

For the question about what doesn’t vary with temperature, one of the answers was something like “deviations from ideal behavior”

Chem doesn’t have a curve as generous as physics, but it’s not like you can’t miss anything to get 800. Prob 4-6 I’d say.

For those who are really concerned about curves, I suggest you go to previous threads like May and January ones, people will say that they think they missed blah blah blah and got blah blah blah

I got -555 for one of the answers. Right?

it was actually -795 KJ.

@Arpeggio206 there was an answer with 555 (don’t remember if there was a negative though)

there was a negative, but you forgot to multiply by two with the 240.

Does anyone remember what the correct hydrocarbon was?

@blandscreenname C4H6

so was 555 the answer or no?

I got -555 KJ for the energy stoichiometry one with the 2220 KJ/mol, and for the heat of formation one, I think I might’ve answered -795 KJ, not sure though.

@picats3141 Those are what I put.

Isn’t the hydrocarbon one asking you about double bond? Then that must be a Alkene right? At least it has to have a formula of CnH(2n-2)
Will someone explain that one?

@tina23 question asked for hydrocarbon with two double bonds

@tooeasy
I see, then I’m wrong, C4H6 it is