<p>Same here skyway. I only studied electrochem, nucleonics, and organic chem last night… none of it was on it!</p>
<p>I got TTCE for the neon one too! And I said TTCE for the compounds families one.</p>
<p>Are there any thoughts about what this guy said a few pages ago:</p>
<p>“I think the question about the amphoteric substance was very unfair. Both C and D would’ve worked. NH3 can donate a proton to become NH2-, or receive one to becoem NH4+. And of course HCO3- is. So can someone clarify here?”</p>
<p>Because I put NH3 too. Did i get screwed again? </p>
<p>One final question. Can a 60 Raw get you a 700? Because the Blue Book said that even a 59 Raw is a 700. </p>
<p>StarportDX</p>
<p>(Keep posting guys! Maybe with all our minds, we can cover every question lol)</p>
<p>I thought about the NH3 too, but decided that HCO3- was safer.</p>
<p>I put HCO3- because it’s a common example. And I don’t remember ever seeing NH3 becoming NH2-. Sure it’s technically possible, but we’ve never worked with it in class. Does it even have a name?</p>
<p>NH2-: “Amidogen \A<em>mid"o</em>gen, n. <a href=“Chem.”>Amide + -gen.</a>
A compound radical, NH2, not yet obtained in a separate
state, which may be regarded as ammonia from the molecule of
which one of its hydrogen atoms has been removed; – called
also the amido group, and in composition represented by the
form amido.”</p>
<p>Just to repost this, lol:</p>
<p>One final question. Can a 60 Raw get you a 700? Because the Blue Book said that even a 59 Raw is a 700.</p>
<p>im pretty sure the neon thing is TTCE</p>
<p>Sorry about the double post. But I want to make sure that the following questions were the ones I got wrong and that everyone here is sure that the following is correct as written.</p>
<ol>
<li>The measuring of 27 ml or so was the buret (not the graduated cylinder)</li>
<li>The Lab safety question (I and III were correct. II said that unused chemicals must be returned to original container. And that’s wrong?)</li>
<li>The drop and the slowdown of the pressure with volume was because of condensation (not saturation)</li>
<li>The HCO3- was amphoteric (not NH3)</li>
<li>The CO3-2 was a base (not an acid)</li>
<li>The Polymerization was the one that had the “n” attached (not the one with the carboxl groups?)</li>
<li>The PF3 question was TTCE (that means there WAS mutual repulsion and that also means that mutual repulsion CAN mean polar?)</li>
<li>The question that gave 334 Joules. The answer was 6000 Joules (and not 1002 Joules?)</li>
</ol>
<p>Sorry for such a long post but can someone tell me if those 8 points are correct as I wrote them? Thanks</p>
<p>StarportDX</p>
<p>I believe that 1-7 are correct. I cannot remember 8 sorry…</p>
<p>Everything is correct there Starport.</p>
<p>BTW, the reason why you don’t put back unused materials is because you risk contaminating the rest of the material in the container. Therefore, you always dispose of unused materials.</p>
<p>what do u guys think of 2 skipped and 12 wrong? should i cancel?</p>
<p>Starport, you owe me a book.</p>
<p>Anyway, I put graduated cylinder instead of buret. It just didn’t make sense to me that a buret would be used to measure an amount of something… I thought you use a buret to administrate precise amounts, and not measure them.</p>
<p>I put HCO3-. Can accept a hydrogen or release one. FWIW, I have never seen NH2 before in any chem or chem-related subject.</p>
<p>What did you choose for the one with an oxide of C? I found C2O2, but I am not sure if it’s the right answer.</p>
<p>For the one with neon I put T T CE, but I am not sure either.</p>
<p>About the amphoteric question, It’s definitely HCO3-. It’s true that NH3 can form NH2- or NH4+, but NH2- does not exist in a solution with water (it reacts with water to form NH3!) and amphoteric substances are usually considered the ones that can act as an acid or a base IN WATER, and NH3 cannot.</p>
<p>And about the buret vs cylinder, it’s definitely the buret. Think about it: when you mesure a volume with a cylinder, you put then the content into another flask or something. You don’t work further on with the cylinder itself. So when you move the measured content, some drops may remain to the cylinder’s flask. And when you need exact measures, where a difference of 0,1 mL matters, it’s not OK. When using burette, you measure the exact volume that goes out. I’ve read it in a very good lab book and I don’t doubt it’s authenticity.</p>
<p>Yeah, but it never mentioned the stage of the procedure. The graduated cylinder could just as well measure a precise amount of a final substance (the result of a lab, for example), while the buret is better for administering precise amounts of an initial substance (a component of a lab, for example).</p>
<p>I thought it was a pretty bad question; it needs some context.</p>
<p>But even if it were a final amount of substance, you still have to add it from another flask and some drops of substance can remain at the top of the cylinder and you get a less volume. I generally avoid measuring anything with a cylinder if I can dispose of a pippete or burete</p>
<p>But if it were a final amount of a substance, a graduated cylinder would be a better choice than a buret. I see what you’re saying but I don’t think that it’s that simple; the buret is the best choice for an initial setup and the graduated cylinder is the best choice for a final result.</p>
<p>Also for the oxide thing I believe I put C2O3 or something of the sort. I reasoned that since half a mole of O2 gas would be reacting with the unknown oxide to produce CO2, 2 moles of CO2 would be produced and the reaction would require 1 mole of C2O3 (C2O3 + (0.5)O2 -> (2)CO2). I’m probably wrong though; I couldn’t think straight for half of the test. Plus the answer you suggested (C2O2) actually exists… carbon monoxide dimer. I’ve never even heard of C2O3… :/</p>
<p>
[quote]
Anyway, I put graduated cylinder instead of buret. It just didn’t make sense to me that a buret would be used to measure an amount of something… I thought you use a buret to administrate precise amounts, and not measure them.
[quote]
</p>
<p>That’s exactly why I chose graduated cylinder. I’ve never used a buret to measure anything… and you CAN get an accurate reading on a 50 ml graduated cylinder. Idk.</p>
<p>As for the NH3 vs HCO3-, you must always choose the BEST answer.</p>
<p>Put C2O3 for the oxide one.</p>
<p>So did I tux.</p>
<p>Wow u guys can remember lots… we can write a book!! hha</p>
<p>hmm im guessing 9 wrong, 3 blank. Can u guys calc. a score for me??</p>
<p>What did you get for the last T/F question about the metal?
The second part was about how metals contain both positive and negative ions.
I got TF.</p>