Ap chemistry post test discussion [2011]

<p>Not sure about the reagent, but if for some reason you spill some acid on the table (especially 16M HBr, nasty stuff), you should neutralize it with baking soda (NaHCO3).</p>

<p>Now after I’m done with the test, all I want is to cry
OK, I can’t believe it’s that hard
The MC is not that hard, but the FR is…
OK, for Q1, I’m good with a & b, but then guess on c and did not do d:((
Q2: OK
Q3: The lab question, which is fine. Still got minus 2:((
Q4: What the h*** is that? My teacher didn’t cover it. Totally get minus 5 out of 15 for Q4
Q5: a/ Good
b/ What the h*** is that equation<br>
Q6: a & b: What the h*** is that?
c: what is that? </p>

<p>So, in short, TOTALLY BLEW IT UP
My aim is a 5, but now I don’t know if I can even get a 4, but not as bad as a 2 (b/c my MC is fairly OK). So my guess is a high 3, low 4:((</p>

<p>Good thing that I did that last night instead of making my battery =P</p>

<p>(applause)! :D</p>

<p>Yeah, that seems reasonable mathisfun. I also earned today that leaving a fume hood open wastes a 1000$ per year! My chem teacher leaves the fume hood open…so I’m not sure.</p>

<p>ah! no i washed my hand yesterday with saturated solution becuse i thought it wouldn’t react with… my skin. i really should have chosen something that would actually neutralize the acid on my hands huh?</p>

<p>Idk if this is enough to give anything away…
but was #5 the one with [deleted]?</p>

<p>I’m not sure why in school labs sometimes it’s not necessary to use a volumetric flask, like when you want to make a solution that is a particular molarity. Does anyone know?</p>

<p>heyhey guys~ i’m doing a lab tomorrow… and just wondering, if I wanna dilute a strong acid, do I add water to the acid or add the acid to the water? pls help ;)</p>

<p>Yes it was. You might want to edit yours though because it’s too specific.</p>

<p>i think it has to do with precision. in my last lab, the sigfigs only went up to ~20ml. the .1 after it didn’t matter because the lowest sigfig didn’t reach. just an assumption though, don’t take my word for it</p>

<p>&
acid to the water. i remember my teacher saying something about it not splattering that way</p>

<p>@roo, add acid to the water! That way, the highly exothermic reaction’s release of heat can be absorbed into the water, and not result in something disastrous!</p>

<p>omg i just realized i wrote the complete balanced equation for all of FR #4
darnn… that’s like 3 marks off…
did anyone else make the same stupid mistake as me?</p>

<p>So is it ok to wash my hands with tap water after messing with reagents? I really don’t want to hurt myself! :P</p>

<p>um i’m pretty sure i got all of the net ionic equations wrong except for the last one because it was similar to the one on the example box. i totally misunderstood what they wanted me to do :(</p>

<p>Awww =(…That sucks man</p>

<p>@mathisfun, did you spill acid or base on yourself? I don’t think you should rinse with tap water if you did, but I may be wrong :S</p>

<p>Roobear, I am confused about what you did? You wrote the balanced equation in the answer box? What’s wrong with that?</p>

<p>Ok so for the predicting reactions -
If the questions says that something is solid before but then it’s put into solution, do you write the Net Ionic equation or just the equation with said compound solid. Also were (aq), (l), (g), etc… required?</p>

<p>EDIT: Also I loled at the “hey I spilled acid… lets throw on some NaOH as well!” (hint… a certain buffer used in blood… )</p>

<p>No for the (aq) stuff</p>

<p>states (aq,l,g) were not required. i’m surprised they let us use pencils on the frq this year…?</p>