<p>so for the color change / redox titration question... the solution went from purple to clear?? or purple to yellow/brown?</p>
<p>I think I got 3.38 for the pH and I'm pretty sure I did it right. I didn't use Henderson-Hasselbach though, just the buffer method, but it should turn out the same.</p>
<p>The solution went from clear to purple.</p>
<p>I got 3.319, which is what many others got as well.</p>
<p>clear to purple and not the other way around? i thought the permanganate made it purple and the Mn ions at equilibrium made it clear.... ugh</p>
<p>oh justttttt kiddinggggg now i get it. oh darn</p>
<p>as you add the purple permanganate, it reacts with the iron and turns to Mn2+ which is clear. When you reach the endpoint, you run out of iron, so the permanganate doesnt react, and the solution turns purple.</p>
<p>iron is clear? i thought it was redish</p>
<p>Iron is brownish I believe</p>
<p>Omg, I just looked at Form B and it was a joke, form A sucked >_></p>
<p>iron is yellow....</p>
<p>wait Fe 2+ is yellow/greenish, Fe 3+ is Brick red, Mno4- is purple and Mn2+ is pink so what do we do? do we just mix the colors?</p>
<p>Ooh sorry, I was thinking about Iron ions lol</p>
<p>i have a question. i was running very low on time so i skipped the MV question and then came back to it later. if i put 1 mole for the first answer (which is obv blatently wrong) but then purposely used 1 mole to find my answer of 55.8 g in the second part wouldnt i get full credit for the second part?</p>
<p>^ my teacher says if you all the steps right you should get full for that part of that question</p>
<p>So um, is it bad if I forgot to use sig figs? I know I did well on the FRQ, and I don't want my score to go down cause of sig figs...</p>
<p>Generally how many people get perfect scores on the equilibrium q? Do these people usually get 5's on the test? I have always wondered where i can get past year's tests score commentery.</p>
<p>um i got 8.16 that way too</p>
<p>I got 3.26 for the pH somehow, hope they don't take off too many points
for the second reaction, i am starting to think i did it completely wrong
H+ + CaCO3 >> CaO + CO2 + H2 is there ne reason that is not correct
for the temp i got something in the 940-950 region which i am almost positive about
overall, i felt as if fr was much easier than i anticipated</p>
<p>nebody have consolidated list of answers?</p>
<p>That decomposition into CaO and CO2 is something that occurs upon heating, not in a metathesis reaction. There's also no reason for H2 to just spontaneously form without the H+ interacting with anything - your equation doesn't even have the HNO3 and CaCO3 reacting with each other.</p>