October 2009 SAT II - Chemistry - Page 5

swim2daend · 10-10-2009, 08:52 PM

idk christian. i thought quantitative chem is kinda hard without a calculator regardless of the numbers

mowmow721 · 10-10-2009, 08:53 PM

Sorry to repost, this is really bugging me.

What did you guys get for the how many moles to react with Cd in the redox reaction (had to balance it to see). I pretty much ran out of time, so I had to skip it and guess wildly.

and then what did you guys get for the VERY LAST balancing question? (like number 65 almost). I got 6, but i had like 20 seconds to do it.

swim2daend · 10-10-2009, 08:54 PM

idr the 1st question. i got 6 for #65 too though

mowmow721 · 10-10-2009, 09:00 PM

Yeah overall I think I got almost all of them right, but I grossly underestimated how much time we had. I also didn't realize there were 85 questions, I thought there were 80. So imagine my shock when I had like 4 minutes left and I turn the page and realize there are 7 more questions to do instead of 2.

JackB427 · 10-10-2009, 09:11 PM

yeah, 6 for the H2O in the last balancing one. and u need just one mole of Cd in the redox reaction cuz Cd was losing 2e- and nickel was gaining 2e-. and when u just had one, u were able to balance the equation without changing the coefficients of any terms with Cd or Ni

JackB427 · 10-10-2009, 09:13 PM

Also, for the ideal gas in a rigid container and the temperature is being increased...was the answer the the pressure increases also since the volume can't decrease cuz it's a rigid container?

mowmow721 · 10-10-2009, 09:15 PM

Temp increases in rigid container, pressure increases.

Can someone confirm that the Redox reaction balancing question was just one mole of Nickel something to just one mole of Cadmium? The question basically said HOW MANY MOLES OF NICKEL SUBSTANCE (It was a ionic substance I think) DO YOU NEED TO REACT WITH 1 MOL of CD....? If Jack is right, I totally guessed that right randomly.

JackB427 · 10-10-2009, 09:20 PM

I'm 100% sure that it's one mol. dont worry; u got it right lol.

slimyworms · 10-10-2009, 10:29 PM

ok so what was the SF4 and the PF4 question?

slimyworms · 10-10-2009, 10:35 PM

oh and wasn't there like 75 questions or something? I don't remember that there were 85...or im just mistaken... i remember the last two questions were on the right side..right?

shen0211 · 10-10-2009, 11:50 PM

btw, are all the questions weighted the same, or is the T/T/CE graded like the math grid-in questions for the SAT.

i.e. if you miss one of the T/T/CE questions, do they still dock the .25 raw-score-wise?

christiansoldier · 10-11-2009, 12:02 AM

Yes, all questions are weighted the same.

djp030994 · 10-11-2009, 12:33 AM

hmmm
do you guys think i should have canceled?
i got everything you guys discussed right (ironically) but the following questions are the ones i got wrong or im not sure:
1) the kinetic molecular thing: i put "pressure is a result of collisions" cuz i forgot (we had to choose the false one)
2) the carbon dioxide denser than air thing.. (i think i put false for that or sth)
3) the exothermic reaction for the first question.. (i put endothermic) question was sth about the reaction of a strong base and strong acid results in the formation of water
4) the au3+ thing with the table of voltages

and plus some others maybe... (omitted none) it was easy but i dont think i prepped that much
btw were we supposed to get 4 ttce's?

3ntropy · 10-11-2009, 06:19 AM

@mowmow721

yup, it's 1 mole. just look at the starting and ending oxidation states. Cd went from 0 to 2+, Ni went from 2+ to 0. so the reacting ratio is 1:1.

mowmow721 · 10-11-2009, 08:44 AM

1) I believe the FALSE one was all gas molecules move at the same speed.
2) CO2 IS denser than air.
3) T,T. H2O is a product, and neutralizations are always exothermic. Not the reason though.
4) Au +3 has the highest reduction potential (At least that's what I THINK the question was asking)