Alkaline Water Facts

Wren asked:

help with any of these questions would be greatly appreciated!!

Use the following redox reaction to answer all of the questions:
Sn2+(aq)+Al(s)—>Sn(s)+Al3+(aq)
1. Balance the reaction
2. What is the reduction half in the above reaction?
3. What is the oxidation half?
4. Could the reaction be used to create a galvanic cell as written? If so, what reaction would occur at the anode? What reaction would occur at the cathode?
5. Determine the standard cell potential for the galvanic cell.

William S asked:

If the reduction half-reaction Cd(2+)(aq) + e- ? Cd(s) has to be multiplied by 2 to balance the electrons before you add it to an oxidation half reaction, what is the electrical potential of this reduction half reaction?

I got an answer of -0.40 V. Am i correct?