CuS is oxidized by molecular oxygen to produce gaseous sulfur trioxide and solid copper (II) oxide. Write 2 balanced half reactions

Answer 1

CuS + 2O2 ==> CuO + SO3

(S^2- ==> S^6+ + 8e)
(O2 + 4e--> 2O^2-)

You want to make the electron gain/loss equal so multiply eqn 1 by 1 and eqn 2 by 2 like this, then add them together.

1*(S^2- ==> S^6+ + 8e)
2*(O2 + 4e-->2O^2-)_
________________________________________S^2- + 2O2 ==> s^6+ + 4O^2- and rearrange to
S^2- + 2O2 ==> SO3 + O^2- Note that this doesn't contain the cu(II) ion but you can add that if you wish.

Answer 2

I did it right thank you for confirmation!