June 2010: Chemistry

Test Preparation SAT Subject Test Preparation
421

<p>The question with the density of methanol or whatever and water, I remember the answer was A or like 0.79 or something. You have to take into account the mass of the container it’s in. </p>

<p>The compound with a lone pair is NO2 because N has 5 valence electrons and O has 6. 6+6+5 is 17, making it the only free radical.</p>

<p>CO2 is linear. </p>

<p>The element with multiple oxidation states was Ti 3+ and 4+</p>

<p>You do not need a bunsen burner for the titration. Titration is releasing a titrant into a solution to find the equivalence point or the endpoint, which is when the indicator changes color. You would need the balance to measure out the quantity of salt you have so you can figure out what the molarity of the titrant, and therefore the solution being titrated. </p>

<p>The oxidation number for Bromine in RbBrO3 was 5+</p>

<p>X2O3 is B and Fe only. Which I believe is I and II.</p>

<p>You separate Ink by Paper Chromatography</p>

<p>A Hydrate is a Crystalline solid with Water</p>

<p>A Hydride is a Metal with Water</p>

<p>CO2 is the least harmful gas when inhaled in small quantities (We breathe it out every day and we live in a society full of automobiles that use gasoline, Duh)</p>

<p>Organic Compound is a Hydrocarbon</p>

<p>N2 has the triple bond</p>

<p>NH3 (Ammonia) is polar</p>

<p>There was a precipitation reaction, a decomposition reaction, and a Redox Reaction</p>

<p>There was a balancing problem where the coefficient for H2O was 4</p>

<p>There was a balancing problem where the coefficient for Oxygen was 3</p>

<p>Highest pH is NaOH. Highest pH means Greatest [OH] and Least [H+]</p>

<p>1 L of O2 was left over</p>

<p>Greatest volume was 400 K and 1 atm. Plug it into PV = nRT</p>

<p>Boiling point is reached when Vapor Pressure equals Atmospheric Pressure</p>

<h1>23-25 The first one was 1 - 2, second one was E, the last one was 1 to infinity</h1>

<p>1.0 M HCl</p>

<p>0.1 M HCl has a pH of 1</p>

<p>The organic question with 16% Hydrogen and MM of 100 is 7 carbons and 16 Hydrogens.</p>

<p>CCl Square Planar [F] Bond Lengths are the same [T]</p>

<p>Isomers were I and II</p>

<p>Salt water solution would have a LOWER freezing point and a HIGHER boiling point, use the T = Kim equation</p>

<p>Those are the ones I remember.</p>

422

<p>@Light</p>

<p>CO2</p>

<p>No covalent</p>

<p>Does anyone else remember the lower freezing point?
I remember thinking about it too. I could’ve sworn it said same</p>

<p>Also, what’s 14.7…what was the question and how did you solve it?</p>

423

<p>lol wasn’t the least dangerous gas CO2…I mean, it’s inside us, it can’t be too dangerous.</p>

424

<p>I agree with all your answwers…However wasnt the question about the MOST harmful gas???(SO2)</p>

425

<p>What do you think the scale is?</p>

426

<p>Howd you do the 16% hydrogen question??</p>

427

<p>The element with multiple oxidation states was Ti 3+ and 4+</p>

<p>Boiling point is reached when Vapor Pressure equals Atmospheric Pressure</p>

<p>I thought Fe was the multiple oxidation states?
I don’t remember the boiling point one, can you elaborate?</p>

428

<p>And why the hell does an 85 question test (5 more questions than bio–> which is just pure fact recall!) have such a crappy curve??? ■■■ :(</p>

429

<p>@Perfectpixie</p>

<p>The question was asking for a compound with a MM of 100 g/mol and it says Hydrogen was 16% by mass. So then, that means 16/100 grams has to be hydrogen.</p>

<p>100-16=84</p>

<p>84/(12.011) <– The molar mass of Carbon</p>

<p>Gives you 7 Carbons</p>

430

<p>@PerfectPixie</p>

<p>Nope, it was the least harmful. That portion is like… descriptive chemistry. It’s common knowledge. Collegeboard wouldn’t test you on the MOST harmful because not everyone has taken environmental science or learned about pollution. Collegeboard will test on common knowledge, which is that humans breathe in and out Carbon Dioxide everyday.</p>

431

<p>■■■ the answer is 14.7
Somehow, I thought .5 * .2 was .01 and I went back with 1 min left to change it. -.-</p>

<p>And how can Calcium substitute X for X2O3?
The charge on that would be +3, and Ca is +2 only.</p>

432

<p>For the X2O3 question, how is it both Ca and Fe???</p>

<p>If you’re not sure of something, please don’t post it.</p>

433

<p>The element with multiple oxidation states was Ti 3+ and 4+</p>

<p>Boiling point is reached when Vapor Pressure equals Atmospheric Pressure</p>

<p>I thought Fe was the multiple oxidation states?
I don’t remember the boiling point one, can you elaborate?</p>

434

<p>@ Hifemale ; I agree with your answers except for:</p>

<ul>
<li><p>How would Ca work for X2O3? Ca would make CaO with oxygen? I put B and Fe. Since it’s possible for Fe to take on a +2 charge, and B2O3 is an existing substance. ( [Boron</a> trioxide - Wikipedia, the free encyclopedia](<a href=“http://en.wikipedia.org/wiki/Boron_trioxide]Boron”>Boron trioxide - Wikipedia) )</p></li>
<li><p>For your ‘greatest volume’ question, was that the greatest molar volume of gaseous hydrogen or something? I can’t really remember, but I don’t think I put 400 K and 1 atm. I rearranged my PV = nRT to resemble n/V = P/RT. I think I might’ve put A? 273 K and 1 atm? Isn’t 1/273 > 1/400, or am I just completely missing the point of this question?</p></li>
</ul>

<p>Thanks!</p>

435

<p>What was the “14.7” question?</p>

436

<p>Whoops that was a Typo. It’s I and II, Fe and B. Sheesh Calm your panties.</p>

437

<p>coup-</p>

<p>I put Boron and Fe as well!</p>

438

<p>■■■ the answer is 14.7
Somehow, I thought .5 * .2 was .01 and I went back with 1 min left to change it. -.-
^^ I don’t remember that at all. What was it about?</p>

<p>Curve prediction? Doesn’t -2/-2 omit and -1 wrong seem ridiculously harsh? The official practice test came from a really long time ago, so it might be different?</p>

<p>OMG I AM SO F***ed</p>

439

<p>@hifemaleseanfeng-
Thanks!! Now i remember evn i got the same ans (7 carbon atoms).
However i read the least harmful gas question wrong darn it! :(</p>

440

<p>okay so let’s say, 1 atm and 273 K</p>

<p>PV = nRT</p>

<p>(1)(V) = (1)(hera;oierh)(273)</p>

<p>We can disregard the number of moles and the constant because it’s the same after you plug it into each equation. so then technically, through eliminating the number of moles and the ocnstant, it’d be 273.</p>

<p>Now look at 1 atm and 400K.</p>

<p>(V)=(1)(arhga;reoig)(400)</p>

<p>The volume would be 400, (if you eliminate the number of moles and constant because they don’t matter)</p>