Chemistry redox question help?

Copper commonly occurs as the sulfide mineral CuS. The 1st step in extracting copper from CuS is to dissolve the mineral in nitric acid, which oxidizes the sulfide to sulfate and reduces nitric acid to NO. Balance the equation below using oxidation states, and assign oxidation states to each atom in the reaction.

CuS(s) + H+(aq) + NO3^-1(aq) --> Cu^+2(aq) + NO(g) + SO4^-2(aq)

Any help would be appreciated~!

Answer:
CuS: Cu+2 and S-2
NO3-: N+5 and O-2
NO: N+2 and O-2
SO4-2: S+6 and O-2

S is oxidized going from -2 to +6, a change of 8 electrons
N is reduced going from +5 to +2, a change of 3 electrons
To balance the electrons, you need 3 S (24 electrons lost) and 8 NO3- (24 electrons gained)

3CuS + H+ + 8NO3- --> 3Cu+2 + 8NO + 3SO4-2
While the electrons, S, Cu and N are balanced, the H and O aren't. You have 24 O on the left side and 20 O on the right side. That tells you that you need 4 H2O on the right side, and 8 H on the left side-

3CuS + 8H+ +8NO3- ---> 3Cu+2 + 8NO + 3SO4-2 + 4H2O

You could make things easier by making copper a spectator ion, but your teacher might not like it.

4 H2O + CuS = Cu(2+) + SO4(2-) + 8 H(+) + 8 e(-)
That's you're oxidation S goes from (-2) to (+6)

3 e(-) + 4 H(+) + NO3(-) = NO + 2 H2O
That's your reduction. N goes from (+5) to (+2)

Multiply first rxn through by 3, second by 8, and add up!

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