AP Chemistry Review Thread

<p>Can the molecular mass of a substance be determined by measuring the freezing point depression of a solution of the substance?</p>

<p>it was funny because in the thread for this year's ap bio exam predictions, 2 ccers said their teachers predicted so-and-so to be on the FR portion. of course, none of them were on when i took it today :[</p>

<p>Yes, you find T = iKm and the molality tells you # moles
you need to be given the mass, so you can calculate molar mass</p>

<p>my friend told me ap bio was really hard</p>

<p>swtnsourbebe...you're taking ap bio AND ap chem??? that is like death lol</p>

<p>@kinsckfan</p>

<p>The answer to his question is no. You're looking too much into it. They gave no other info but what he said.</p>

<p>ya same equation swtandsour
usually if a question involves Q, they'll give you a value for Ksp to begin with, and tell you that they changed the concentrations a little to yield Q.</p>

<p>afruff, yes you are right...sorry about that confusion</p>

<p>I don't want the FR to be on buffers... I hope your teacher is wrong :)</p>

<p>i hope so too</p>

<p>I actually like the equilibrium problems very much. They'll probably be the easiest part of the FR for me... Writing equations shouldn't be all that bad, but whatever else they put on there is oh-so unexpected. Oh, and lab questions = not good, but they'll inevitably be on there.</p>

<p>hey guys, how much do we need to know the Svante Arrehnius equation for the FR?
Should we be experts at it or it more than likely not gunna appear?</p>

<p>i hope my teacher is wrong too! </p>

<p>i don't think we'll need to know arrhenius equation</p>

<p>yeah..i'm taking bio and chem. let's say bio is SO much easier than chem. the exam wasn't too horrible. tonight is the only time i'm preparing for chem and i'm hoping that i at least get a 3</p>

<p>oh ok, so there hasn't been any arrehnius equation on the recent kinetics FR questions?</p>

<p>@kinsckfan & afruff
it was one of the sample questions.</p>

<ol>
<li>The molecular mass of a substance can be determined by measuring which of the
following?
I. Osmotic pressure of a solution of the substance
II. Freezing point depression of a solution of the substance
III. Density of the gas (vapor) phase of the substance
(A) I only
(B) III only
(C) I and II only
(D) II and III only
(E) I, II, and III</li>
</ol>

<p>The answer is E....</p>

<p>so...</p>

<p>what is the equivalence point and halfway point of a titration?
which is when pH = pKa?</p>

<p>you think they will make us go into detail about the subdivisions of main energy levels?</p>

<p>equivalence point is when concentrations of H+ and OH- are exactly equal. the end point of the titration should occur soon after you reach the equivalence point-its due to an excess of OH- or H+. the solution will change color accordingly</p>

<p>I'm going to bed guys, good luck to you all!</p>

<p>thanks good luck to you too!</p>

<p>i live in nj, at it's 11:30 pm...my exam is in about 8 hours :(</p>