Chemistry 2010 Exam

pkm2232
Sun, 16 May 2010 20:37:48 +0000

This year’s wasn’t necessarily difficult but it was not straightforward. Since nobody seems to be doing this, I’ll start:


a. Ksp=[Ag+][Br-]
b. about 7 x 10^-7 M
I forget the rest of the problem except I got about 37000 L (prob. very wrong) for the one about how much needed to completely dissolve 5g and the AgBR was more soluble because the AgI precipitated first.
a. lowered by 3.2oC
b. Endothermic, b/c it took in heat energy from surroundings
c. something like 1200 j or so ???
the percent error one was 12.46 kj/mol
I don’t remember much, but I think the rate law was rate=k [first species]^2[Second species][H+]^3
Also, it could not have happened in one elementary step because it involves 3 molecules and termolecular collisions are not conisdered elementary.
first one was KOH + HNO3 –>H2O, but all you wirte down is OH- + H+ –>H2O because they both dissociate 100%
Ethyne: H:C:::C:H
Either Ethane or Ethyne could have been used for the nonpolar one
The IMFs one dealt with one having H-Bonds, so it is more soluble because things with similar IMFs dissolve and the other was dipole-dipole so it only dissolved somewhat.


@ lemone: did you take form B? I don’t remember it asking geometry questions.