Chemistry Help Forum

<p>I am currently in Chemistry (obviously). I attend an online school that uses multiple websites to teach the course. These websites are just terrible. They are so bad that I am looking up the information on other sites, but that it draining a lot of time. What textbooks are you guys using? Do you have any you recommend, or alternatively, that I should stay away from? I am really desperate - even a mediocre textbook would be welcomed at this point. Thanks!</p>

<p>bump. I would appreciate any suggestions</p>

<p>Well, I haven’t used any other books apart from the Barron’s and I would recommend that one.</p>

<p>Hey guys! I’m thinking of taking the Chemistry SAT II, preferably in January. The thing is, all I’ve taken is Honors Chem last year, where I got a 91 with absolutely no studying. I love chem, but I’m not sure if you can self study for the Chem SAT II. Chem is the only science I like, so I’d really like to do it…is this possible? Any advice.</p>

<p>Are we expected to answer questions like:</p>

<p>A compound that can be decomposed to produce oxygen gas in the lab is
A) Mn 02
B) NaOH
C) CO2
D) KClO3</p>

<p>answer is D.</p>

<p>How would we figure it out?</p>

<p>There was an experiment in Barron’s book that had a diagram of the producing oxygen.</p>

<p>@hannahbanana94</p>

<p>It is totally within question to get a great score through nothing but self studying. However, you said that you got a 91 without studying, which I take to mean that you are smart enough to be able to either retain lecture information or retain crammed material (that’s how I am), so you probably have a knack for info retention as it is. As long as you have a solid knowledge of the basis of the information, you can self study effectively for anything. Just get one or preferably two prep books (PR and Barrons) and rip 'em up. Good luck.</p>

<p>@redzerb</p>

<p>Thanks, my Chem teacher last year actually lent me Barrons, and I’m just planning on reading a chapter a day, and repeating the cycle a few times. I hope to take it for the first time in January, though that might be a litte too fast. I basically just have a knack for understanding Chem, and so I was able to get by last year by just kind of listening in class. I’m really looking for around a 750, but I don’t know if I can do that.</p>

<p>guarantee you can.</p>

<p>What is the maximum number of moles of PbSO4 that must be used to prepare 1L of saturated PbSO4 solution at 25 degrees Celcius…(Ksp at 25 degrees Celcius of PbSO4 is 1*10^-8)</p>

<p>The answer is 1*10^-4.</p>

<p>I would be glad if anyone could explain to me how to go about the question.</p>

<p>Thanks in advance.</p>

<p>yeah i don’t understand that one either. I didn’t know that a saturated solution had a necessary molar concentration at a given temperature. Where did that question come from?</p>

<p>I saw the question in an older version of the SAT Subject Tests Preparation booklet. Some one has explained it to me. </p>

<p>…PbSO4------->Pb^2+ SO4^2-
I…some # (s)…0…0
C …-s …+s…+s…(the dots are for formatting)
E…total-s…0+s…0+s</p>

<p>The Ksp equation would be:
A----> nB + xC
Ksp= **^n [C]^x</p>

<p>so…</p>

<p>Ksp= [Pb^2] [SO4^2-]
1<em>10^-8= (s)(s)
1</em>10^-8= s^2
s= √1<em>10^-8
s=1</em>10^-4</p>

<p>1.Which of the following does not react with dilute solution of H2SO4…
A) NaNO3 B) Na2S C) Na3PO4 D) Na2CO3</p>

<p>Barrons says the answer is A because NaNO3 requires heat to react with H2SO4</p>

<ol>
<li>A student made the following observations in the laboratory.
(a) Sodium metal reacted vigorously with water while a strip of magnesium did not seem to react at all.
(b) The magnesium strip reacted with dilute hydrochloric acid faster than an iron strip
(c) A copper rivet suspended in silver nitrate solution was covered with silver-colored stalactites in several days, and the resulting solution had a blue color
(d) Iron filings dropped into the blue solution were coated with an orange color</li>
</ol>

<p>The order of decreasing strength as reducing agent is
(A) Na, Mg, Fe, Ag, Cu
(B) Mg, Na, Fe, Cu, Ag
(C) Ag, Cu, Fe, Mg, Na
(D) Na, Fe, Mg, Cu, Ag
(E) Na, Mg, Fe, Cu, Ag</p>

<p>I noticed the are questions on gases on each practice test I have taken so far. Does anyone have a comprehensive summary on the solubilities and densities( whether they are heavier than air or not) of the common gases. I would be great if anyone could share it with us. I remember we were once taught how to determine whether a gas is denser that air or not, but I do not remember how to go about it. Anyone knows that…(what is the molar mass of air)</p>

<p>Bump Bump.</p>

<p>Are there generally questions about hybrid orbitals, pi bonds, sigma bonds, etc? Also, do I need to know a lot about organic chemistry (like alkenes or functional groups)?</p>

<p>I usually see 1-2 questions on orbitals, pi and sigma bonds. I rarely come across questions on organic chemistry though.</p>