[hunter457]

For both of these problems, I'm having trouble writing the half reactions. How do I know how many e^- to put and on which side of the equation do they go?

1. The following redox reaction occurs in basic aqueous solution. Balance it with the smallest whole number coefficients and determine the coefficient for the hydrogensulfate anion.

Al(s) + HSO₄^-(aq)  Al₂O₃(s) + S₂^-(aq)

2. The redox reaction below occurs in acidic solution. Balance it with the smallest whole number coefficients and determine the coefficient for H₂O.

Zn(s) + NO₃^-(aq) ---> Zn₂⁺(aq) + N₂O(g)

[hunter457]

Actually, I figured out that you balance the atoms and then only add electrons to balance the charges on both sides of the equations.

So:

1) 3
2) 5

Is that right?

[Borek]

Looks OK, even if your formatting was confusing.