<p>What do we need to know about quantum theory for SAT Chemistry? Does PR cover sufficient amount?</p>
<p>Er, to be honest I barely know what the quantum theory is and I still got 800, so I wouldn’t worry about it TOO much. PR is okay, but it has some pretty detrimental typos. But then again, pretty much all of these prep books do…</p>
<p>Just interested, what typos?</p>
<p>Like, they messed up the Henderson-Hasselbalch equation (they mixed up acid and base in the fraction). It was kind of ironic because right before they did that they mentioned that a lot of people get that equation wrong. But my edition was kind of old, so it’s possible that it’s corrected in the newest version.</p>
<p>Random question</p>
<p>Do we need to memorize really obscure things like colors?</p>
<p>Also, how much detail do we need to know about Quantum numbers?</p>
<p>Yep, colors show up once in a while. (I know, it’s really annoying.) And you should definitely know quantum numbers - basically, just how to write them for any given element.</p>
<p>know quantum numbers and memorize colors for solutions</p>
<p>Could you name some important colors?</p>
<p>You don’t really need to know the color of a given solution per se, moreso whether or not the solution has color.</p>
<p>In general, you should know that solutions that contain a cation that is
a) not a transition metal and
b) does not contain any electrons that are unpaired
will be colorless. </p>
<p>For example,</p>
<p>NaCl, MgCl2, AlCl3, and NH4Cl solutions are all colorless. So are ZnSO4 and CdSO4 solutions. </p>
<p>Conversely, transition metal cations with unpaired electrons (Fe, Cr, Mn, Co, etc) all produce colorful solutions. Cu solutions are blue despite the d block being complete, for it still has an electron unpaired in the s block.</p>
<p>Some colors you should know: cobalt solutions are blue (My chem teacher always reminded us of the cobalt crayons, if that helps), MnO4- solutions are purple, copper solutions are blue, and sulfide precipitates (Ag2S, for one) are usually black, while many other precipitates (AgCl, for one) tend to be clear.</p>
<p>ionic solutions with transition metals are colored, non-transition metals are colorless, thats the general rule of thumb.</p>
<p>@somestudent</p>
<p>Only hydrated compounds of cobalt ions are blue. In general solutions, cobalt ions are red.</p>
<p>@Ethereality </p>
<p>I didn’t know about that. You learn something new every day.</p>
<p>What do you mean “unpaired electrons”?</p>
<p>Like Na, in NaCl, has one unpaired electron right? (in the S orbital)</p>
<p>If so, how does it fulfill requirement “b”?</p>
<p>Sorry, that should’ve been “or” rather than “and.”</p>
<p>Na does indeed have one unpaired electron in the s orbital.</p>