<p>unfortunately i think the scoring will be one point for each expression... =/</p>
<p>Will I still get credit for part iii if I put..</p>
<p>5(55.85)MV/(total mass) </p>
<p>I said total mass because i didnt see g there above?</p>
<p>Oh. My. Gosh. I realized that I made the stupidest mistake on the acid problem. I had the NaOH and HF reacting to make NaF... then added in the concentration of F- (from NaF) to the rest of the problem, and applied the common ion effect. Why do I overcomplicate things so much?!?!?! I'm so stupid.</p>
<p>for the first part, couldn't it just be g/55.85?</p>
<p>Is the answer for 1e 3.32 or so?</p>
<p>No, g was the mass of an iron compound, it had other elements other than iron.</p>
<p>optimum - yes.</p>
<p>for the Keq=1 one, with the electrolytic cell,
did someone get a temp of ~900 something?</p>
<p>and electrolytic means that dG is positive right?</p>
<p>renak i got 940 but i think it was wrong, we weren't supposed to use dS and dH i dont think</p>
<p>yes electrolytic means dG is positive</p>
<p>Yeah, negative voltage too. I hope. I treated that problem as a galvanic cell at first, realized it didnt make O2 and Cu like the picture, then remembered covering electrolysis.</p>
<p>Here are my answers:</p>
<p>Question 1:
b) 0.0170
c)0.004
d) 0.1 M
e) pH= 2.56</p>
<p>for part e</p>
<p>7.2*10^-4 = (x(.1+x))/(.4-x) where x is the H+ concentration</p>
<p>Question 2:
a)-181.2 KJ
b) 949.7 K
c)-33.8 kJ/mol
d) 6 bonds
e) 141</p>
<p>Remember that S was given in joules, so you had to either convert it or H into the same units before doing the problem.</p>
<p>can someone refresh my memory as to what 2e was, i can't seem to remember</p>
<p>cross- different pH for e, not sure about b, everything else seems ok though.</p>
<p>2e was find the bond energy of a F-F using delta Hs</p>
<p>did you guys draw SO2 bent? and how many SO2 diagrams did you do..2?</p>
<p>949 was my answer for the temp when Keq =1</p>
<p>I drew both of SO2's resonance structures.</p>
<p>What did you guys get for the electrolysis question? We had done about two days of electrochem... so, I'm not sure if I did that one correctly or not.</p>
<p>Why doesnt delta G = -RT ln(K) work for solving that problem? I know you get 0, but it doesnt make sense to me.</p>
<p>a. counterclockwise
b. dont remember, it was an easy equation though
c. positive
d. 343.487 kJ
e. 1.186 g
f. 0.197 L O2</p>
<p>UGH! I didn't divide 3e by 2. Do you think I'll get any points for that?</p>
<p>And for the titration color change - shouldn't it be purple to clear, not the other way around...?</p>
<p>Hey, I think I got those =)</p>
<p>Well, I thought that you were supposed to use the dG that you had already calculated... there would be no way that a nonzero number could equal zero, no matter what the temperature was. That's why you have to use dH = TdS....</p>
<p>A mike i think 2b was K=0 now that i think about it</p>