Sciencemadness Discussion Board

Help interpreting short text (SOLVED)

flakten - 24-6-2016 at 07:34

I'm just starting chemistry studies in university level. There's an expression I can't interpret.

"...precipitated from aqueous CuSO4..."

How much CuSO4 should there be, should it be 1:1 with the substance which is dissolved and precipitated or just a small presence of the salt to help dissolving the substance?

I'm reading ahead in the books and I'm trying to understand the experiment. This is the one part I've failed to interpret properly, and no search has answered it.

Can you more experienced chemists help me?

[Edited on 24-6-2016 by flakten]

[Edited on 24-6-2016 by flakten]

aga - 24-6-2016 at 07:42

Might be better to post the full text as we can't guess what is being precipitated.

PHILOU Zrealone - 24-6-2016 at 07:47

We would need the original text or at least paragraph to get a better general view of the problem to give you a correct answer.
CuSO4 into water is Cu(2+) and SO4(2-) both the cation and or the anion can be precipitated if correct anion or cation is joined...

CuSO4(aq) + 2 NaOH(aq) --> Cu(OH)2(s) + Na2SO4(aq)
reduced equation
Cu(2+) + 2 OH(-) --> Cu(OH)2(s)

CuSO4(aq) + BaCl2(aq) --> CuCl2(aq) + BaSO4(s)
reduced equation
SO4(2-) + Ba(2+) --> BaSO4(s)

CuSO4(aq) + BaS(aq) --> CuS(s) + BaSO4(s)
reduced equation
Cu(2+) + S(2-) --> CuS(s)
SO4(2-) + Ba(2+) --> BaSO4(s)
--------------------------------------
Cu(2+) + S(2-) + SO4(2-) + Ba(2+) --> CuS(s) + BaSO4(s)

(aq) means dissolved and ionized into water
(s) means solid precipitate

flakten - 24-6-2016 at 08:14

Quote: Originally posted by PHILOU Zrealone  
Cu(2+) + S(2-) + SO4(2-) + Ba(2+) --> CuS(s) + BaSO4(s)


Thanks! Your text was enough for me to understand the experiment.

PHILOU Zrealone - 24-6-2016 at 08:40

I haven't learned pedagogy of chemical science teaching for nothing then :D;):P:cool::)