Official SAT Subject Test - Chemistry - June 2015

hat did you all say for he total number of moles of ions for the reactants of Fe2(SO4)3 in water?

1 mole of Fe2(SO4)3 has 5 moles of ion

I think I read that question wrong :frowning:

So is the consensus on the carbon question sublimation or oxidation?

I think I got two questions wrong, the vapor pressure one and the unpaired electrons one (mainly because I had no idea what the oxidation state of vanadium was). But I might have gotten others wrong (the lab one, apparently?). Hopefully the curve is 81 for an 800!

probably oxidation

Wait but if that was the question, shouldn’t oxidation and reduction both be involved…? Since C changes from 0 to +4 and O changes from 0 to -2.

I think it is just looking at that one specific half reaction of oxidation.

But that is really unclear… We should write a complaint about the problem lol

Can we even do that?

Yea we can.

@Marshmallow99 There is no O in C so it can’t go from 0 to -2. It said C to CO2 and the only element in both is C so C goes from 0 to +4.

But in order to form CO2, the carbon needs to react with oxygen through combustion, right? So then, the oxygen has to be reduced for the carbon to be oxidized, and both processes are involved.

I guess the reduction is implied.

@sonofgod908 is right, that question is oxidation for formation of CO2 from solid C

For the two nuclear chem questions, what did you guys get? For the first one about the 3 choices, I said both 1 and 2 can occur, so choice C or something like that. Then for the one near the end of the test, I put electron

what was the other nuclear chemistry question?

Did anyone get an answer .250 moles for a question I don’t remember? I remember other answer choices were 4.05 moles and 2.00 moles

What were the colors of like the Fe gas and the Cu solid and NaCl?
NaCl was obviously white, I said the Cu one was blue and I like guessed on the Fe gas

Fe2O3 is a brown solid - rust. and I did get 0.250 moles on a question.