<p>The reaction was endothermic, so wouldnt the heat be on the left side of the equation?</p>
<p>yeah I agree with doctor 92 </p>
<p>i thought for that one it was to raise the temperature
it was sth like reactant1 + reactant2 +heat -> product1 + product2
therefore if you increase the temperature the reaction would shift to the right
and increase the amount of product 1
the question said it was an endothermic reaction</p>
<p>hey what did u guyz put for like kinetic molecular theory sth sth
it was like “according to the kinetic molecular theory…at room temeperature and 1 atm”
damn it i can’t remember the question
anybody remember??? </p>
<p>and what did you guys put for the weak acid Ka
it gave you 0.1M weak acid and the [H+] was 10^-3 sth like that
and asked you the [A-]?? ahhh can’t remember
it was like last question i think…</p>
<p>Kipling: are you referring to the question about nitric acid? how the concentration of nitrate is 1x10^-2, then what is the pH of the solution?</p>
<p>The answer was pH 2, I believe
(Actually, I’m guess you’re not talking about this question)</p>
<p>Or… I remember there was this other question about 0.1M? acetic acid. I dont remember my answer though</p>
<p>I think the Ka for that weak acid one was 10^-3. pH was two for the nitric acid.</p>
<p>And Kipling:
The molecular theory one…
I’m pretty sure it’s the atoms will collide with each other and with the walls of the container</p>
<p>The second part of the molecular theory one had something to do with collisions of molecules at a higher energy than the activation energy.</p>
<p>Doctor, wasn’t that the second part of a T/F question? I can’t manage to remember the first part of that question though…</p>
<p>It was one of the T/F questions. The first part may have had something to do with collisions of the molecules with the container and other molecules in the container.</p>
<p>Also, there’s another T/F question I have doubts about…
One about water having a higher boiling point than some other substance?
Anyone recall?</p>
<p>The question stated that water has a higher boiling point than hydrogen sulfide. I said it did not because hydrogen sulfide has a higher molar mass–>stronger bonds? At least that is what I thought during the test.</p>
<p>Oh yea, that’s the question.
I remember putting F/F :O</p>
<p>Water does have a higher bp than hydrogen sulfide. At room temp, hydrogen sulfide is a gas, whereas water is a liquid. You have to raise temp to 100C to boil water and turn in into a gas, thus water has a higher bp</p>
<p>Boiling point of H2S
-60.28 °C (212.87 K)</p>
<p>Boiling point of water
100 °C</p>
<p>So I guess that was T/T/CE? o-o;</p>
<p>water has higher boiling point than H2S becuz there are hydrogen bonds between water molecules which are stronger than the dispersion forces between H2S so yea water is higher bp haha…</p>
<p>for the question about which reaction results in the greatest entropy increase, is it the ch3oh (l) to ch3oh (g) or the reaction zn + hcl ---- zncl + h2? it’s the zinc one becuz they said physical reaction rite?</p>
<p>and the instrument not needed in titration is crucible? i have no idea what’s a heyenmeger flask or whatever haha… i don’t even know what’s a crucible oso haha…</p>
<p>pyrosphere:
For your second question: yes, crucible is the one that is not used, for sure :)</p>
<p>For your first question:
Do you remember all of the choices for that question? I can’t remember what I put – I think I put the (l) –> (g) though… </p>
<p>I can’t recall, but if the question indeed specifically asked for a PHYSICAL change, then I think the answer would be (l) –> (g) because a liquid evaporating is a PHYSICAL change. However, Zn + HCl –> ZnCl + H2 is a CHEMICAL reaction/change, not physical</p>
<p>No, it asked specifically for a chemical change. The question was like: “This chemical change…” I remember specifically reading that.</p>
<p>the Ka one was 10^-5 right?</p>
<p>ah! hm, I remember pondering over chem v physical changes. So maybe I did choose the zinc reaction. Can’t remember now .-.</p>
<p>doctor92, I don’t think boiling point depends on molecular mass. It depends on number of atoms. I said it had a stronger bond because water has hydrogen bonding but hydrgoen sulfide doesn’t.</p>
<p>what was the pH of a .01M NaCl? I said 7 because it’s a neutral salt. Am I wrong?</p>