Sciencemadness Discussion Board

Analysis of Alum Lab

nzerb - 12-10-2014 at 13:28

1.If alum is heated at first too strongly and as a result the alum splatters out of the crucible what effect will this have on the determination of the water of hydration?
2. If alum is heated insufficiently what effect will this have on the determination of the water of hydration?
3. If not all of the alum dissolves in the water before adding Ba(NO3)2 solution what effect will this have on the sulfate percent error determination?
4. If precipitation of BaSO4 is incomplete due to inadequate heating or insufficient time what will happen to the sulfate percent error determination?
5. If the BaSO4 ppt isn't washed adequately what effect will this have on the sulfate percent error determination?
6. If the BaSO4 ppt isn't dried completely what effect will this have on the sulfate percent error determination?

hyfalcon - 12-10-2014 at 13:45

Read your text book and answer your own homework.

Chemosynthesis - 12-10-2014 at 13:48

Just copying lab homework questions with no introduction is kind of awkward. You also posted in the wrong place (beginnings, but it's not a textbook substitute).

DraconicAcid - 12-10-2014 at 14:07

And you do know that some of us are instructors, right? And if your instructor is on this forum, they can recognize their own questions, right?

Polverone - 12-10-2014 at 15:08

Show what effort you have put in already and explain where you got stuck. Nobody is going to just do your homework for you.

Spock - 12-10-2014 at 15:19

You're taking AP chem by the look of things, would i be right?

nzerb - 12-10-2014 at 15:54

I am taking AP Chem ( as a sophomore in hs). I want to know if my answers are correct and an explanation because I do not know why it will result in this way. Thank you.
My Answers:
1. Higher than actual
2.Higher than actual
3. Higher than actual
4.Higher than actual
5. Higher than actual
6. Lower than actual

hyfalcon - 13-10-2014 at 02:18

If you don't understand it, don't be afraid to walk up and ask your instructor. If he's any kind of teacher at all, he will take the time to explain it to you.

nzerb - 13-10-2014 at 08:07

I was able to figure out questions 1, 3, and 4. I understand that #2 is that the water of hydration will be lower but I don't know how to explain it. I am, however, very stuck on questions 6 and 7.

hyfalcon - 13-10-2014 at 11:37

Show your work. That way the instructor will know where you need the help and what you do and do not understand.