***May 2015 - Chemistry***

Also, can anyone post a link to an actual grading curve? like how they score the test

7*10^-4 is that what you guys got?

Yes I got that

Here’s what I got for the couple of contested ones I saw on here:
Saltwater - evaporation
Water Methane - distillation
c9h8o4
Left with 1L of O2
The Na half reaction - I got Solid to a gas (Ei is based on STP so it would have to be a solid, not sure the gas tho)
The DeltaH of CO2 - H2+H3 (Second guessing myself now, but still think this could be right)
Ca vs. CaO - flat line (It can’t have a slope because the % of Ca will always stay constant)
I got a crapton of Trues (not fullout TTCEs) but a lot of trues, anybody else?

Does anyone have predictions for the scoring curve?

DeltaH was definitely H2 + H3.
Left with 1L of O2
Ca vs. CaO flat line for sure.
I think i only put 2 CEs.
The question Li, Na, K have similar properties (T); They have the same amount of Valence Electrons (t) i wasn’t sure if CE so i didn’t put it, is it?
If anyone remembers questions (whether it was easy or hard) please keep posting them

Does anybody remember what the answer to the second to last question was? I dont quite remember the question but my friend and I got different answers.

does anyone else remembering getting the answer SO2 twice in a row in one of the sets of choosing from a list? The first question of the set asked which compound is not a gas at room temperature (the answer was AgCl) and then the two following questions were something like which gas is diffuses slower than N2 and which compound is responsible for acid rain

@baller55 pretty sure it is CE for the Li, NaK one

@wehaveguests I think I got 2 SO2 as well

Wehaveguests yea it was AgCl; SO2; SO2.
Redrabbit the problem is that i can find two counterarguments: group 1 and group 2 elements have similar chemical properties and don’t have same valence electrons; by the same token, h has 1 valence electron and doesn’t have similar properties

Oh I think that was like SO2

Which was the answer to the question asking about a bronstead lowery acid and base… I put HSO3 I think (it may have been Hso4-)

i don’t remember that question, but the question in the ttce section, Hco3- is both acid and base because it canaccept and donate proton is TTCE

@baller55 I think it depends on ones qualifications for how similar counts as similar… I remember doing a pratice test (Barron’s maybe?) and there was a similar question so that’s why i said CE but it could absolutely be not CE who knows hahaha

@TheKrompir123 Yeah, it was a TTCE question. I believe I put TTCE for it. It was like HSO4- is a Bronstead Lowry base and acid and the explanation was it can accept and donate protons.

I got TTCE as well @TheKrompir123

for the question of highest [H+] i put 7x10^-4 but wasn’t sure if it was that (a) or 2x10^-4 [c). i know it was one of those two

Yeah I got TTCE for both the HCO3- one and the Alkali Metal one. I also got 7x10^-4
@baller55

You guys think the curve will be higher or lower than usual. This was the first time I’m taking an actual CB exam (all my practice was from barrons) but I thought this was really easy

@baller55 answer A is a higher value than answer C which means the product side is favored more/ more H+ so I think it should be A?