SAT Chem (yay!!! ahem...) Nov. Study Thread

<p>So…I’ve just started studying for the SATIIChem in Nov. Cram time!
I’m using Barrons and Kaplan… and took 2 practice already (without studying)… the scores were abysmal (real sat II and sparknotes test 1 --620)
In any case… I’ve got some Q’s…
<em>beware of …brainless q’s</em></p>

<li>What is the effect of electron electron repulsion in an atom??</li>
<li>where does the energy for the removal of an election (ionization energy) come from?</li>
<li>When does a molecule become an ion?</li>
<li>What is the trend of successive ionization energies in an atom? in electron subshells s, p, d, f??</li>
<li>Why does K react vigorouly with H2O? What other atom does so as well and why? How can we know if a molecule will react with water?</li>
<li>Density of gases… masses of gases…ideal gas law… someone care to do some explaining? </li>
</ol>

<p>Follow up with anwsers if possible and your own q’s~</p>

<p>haha i took one and got 650... nowhere close to where i want to be but i havent had chem since last year :O. Please check these i dont know if theyre right.</p>

<ol>
<li>Shielding effect? electrons repel each other and make them easier to remove.</li>
<li>The energy to remove an electron comes from the electron affinity of another atom.</li>
<li>Gains/ Loses electrons</li>
<li>Ionization energies get lower when you go down and to the left. noble gases have really high 1st ionization energy.</li>
<li>Alkalines react violently with water. I dont know why. someone else post.</li>
</ol>

<p>!!!!!!!?'s!!!!!!!!!</p>

<p>Gas A is at 30c and b at 20c. what is the ratio of the volume of 1 mole of a to one mole of b?
1:1
2:3
3:2
303:293
606:293</p>

<p>an oxide of arsenic contains 65.2% by weight. whats its simplest formula?
aso
as2o3
aso2
as2o5
as2o</p>

<p>the heat of combustion of gaseous ammonia is 81 kcal/mole. how much heat is evolved in the reaction of 34 grams of ammonia with excess o?
40.5
60.3
75.8
81
162</p>

<p>!!!!!!!!!ANSWERS!!!!!</p>

<p>303:293
as2o5 <this one was hard for me w/out calc
162</p>

<p>im rly confised on the pasrt of the chem test where it asks if the state is true and if the statement following it verfies it and is true or fals and whther it is a correct jutification....can someone explain....i got most of those questions wrong on the practice tests bc i had nooo clue how to do it! </p>

<p>thanks</p>

<p>well,lol</p>

<p>Alkalines react violently with water
cuz the alkalie metal have a valence number of 1, which means each of the alkaline metal atom (Na, K,etc) only has 1 e- in its outershell, which will make it much easier to lose the e- compared to other metal atoms ,whih have more than 1 e in their outershells.</p>

<p>if you start that late..
i have some suggestions.
don't get stuck on some fancy formulars or extremely hard concepts, which the Barron's usually covers and which usually won't appear on the test at all.
you can actually use the outline of concepts coverd on the test from the college board website...
that will make your life much easier...and your prep more effective</p>

<p>i really hope I can do well on this. Aiming for 750+.</p>

<p>HEY I HAVE A QUESTION! in the section where you have to indicate whether it is true, false, and whether the second is a correct explanation of the first...do we get at least half credit if for example the answer is T, F ...and we put T, T? just wondering hehe...or do we just get the whole thing wrong</p>

<p>same question here........</p>

<p>but I believe we will lose the whole mark. if we get one of the T/F thing wrong.</p>

<p>You lose all credit. Even if you put T T and no CE when it should of been T T CE. This is what screwed me from an 800. Got a 770 >.>.</p>

<p>just take a lot of practice tests and the TTCE won't be that hard anymore, that's what I did - got an 800</p>

<p>I have a question....
I put a new thread with the exact same text as this, but I was afraid no one would read it...Can anyone please help me out ?</p>

<p>Anyone who has the big dark blue book REAL SAT Subject Tests from college board(not the new one the official study guide for all subject tests or whatever it is) ...</p>

<p>Question # 59.</p>

<p>Which of the following does NOT react with a dilute H2SO4 solution?
A)NaN03
B)Na2S
C)Na3PO4
D)Na2CO3
E)NaOH</p>

<p>The answer's A, but I'm not sure why...
can someone explain it to me please
I know E is a neutralization reaction, and I think D produces CO2 gas and maybe B produces H2S gas, but I'm not sure about the rest.</p>

<p>And also, if someone can explain how to figure out the answers to questions 5,7,8, and 9 I'd really appreciate it :)
Here's the Problem...sorryT.T I don't know how else to put it:</p>

<p>(OH-) + (5) → (CrO4)^2- + (H+) →(6)→
(Ba)^2+ + (Cr2O7)^2- + (H2O) ←(8)←→(7)→(SO2), (H+)→
(BaSO4) + (9) + (H20)</p>

<p>A)CrO7^2-
B)H+
C)OH-
D)Cr^3+
E)Ba^2+</p>

<p>I just plugged answers in and tried balancing the equations, but that took sooo long...</p>

<p>jh12000: I was also very confused about this problem but in a Barron's book, I read that it was NaNO3 because a reaction of sodium nitrate and sulfuric acid is endothermic while the other ones don't require heat.</p>

<p>I have no clue what your second question is......</p>

<p>I am about 80% sure it cant react with NaNo3 because its a strong acid (at least the No3 part) and h2so4 is a strong acid. All of the others are more basic over adicic. I guess you can't do acidic with acidic etc.</p>

<p>well, sodium nitrate is a salt and under endothermic conditions it would react w/ sulfuric acid to yield sodium sulfate and nitric acid</p>

<p>I see your point w/ acidic and acidic but think of sodium phosphate!</p>

<p>Sorry man. H3po4 is NOT a strong acid. Its possibly the closest though to becoming one. However it is not.</p>

<p>Is it possible that no precipatate will form because of the NO3- ions and Na+ ions are dissasociate in solution?</p>

<p>Check me on that if I am right or wrong.</p>

<p>gyros321: true, but I think the fact that the reaction is endothermic weighs in more.....</p>

<p>marchballer: yes...sodium nitrate would dissociate but that does not prevent the reaction; in fact, all of the possible choices would dissociate</p>

<p>thanks for the answers :)</p>

<p>Sorry to pick up this old topic but I have a small question about the kinda problems that'll show up on the tests. I've been prepping primarily with the PR book but in the last week my friend lent me his Barrons study guide and there seems to be a huge emphasis on the lab stuff in Barrons whereas its not really stressed much in PR. I know the basic stuff but some of these setups are just ridiculous...so basically I'm wondering if those lab q's show up as much on the real test as they do on the Barrons practice tests. Thanks in advance.</p>

<p>no, lab questions are very rare. don't use barrons. it overprepares you for the test and makes you lose self-confidence.</p>

<p>I got an 800 using barron's</p>