Which reaction below will occur when Cd (s) and Zn (s) are added to a solution that contains both Cd2+ and Zn2+ ions?

Question

Cd (s) + Zn2+ (aq) → Cd2+ (aq) + Zn (s)

Zn (s) + Cd2+ (aq) → Zn2+ (aq) + Cd (s)

Both of the above reactions occur.

Neither of the above reactions occur.

Answer 1

Here is a link to the activity series. A METAL will displace another metal ION below it in the activity series.
Therefore, Zn will displace Cd^2+ but not the other way around.

http://www.files.chem.vt.edu/RVGS/ACT/notes/activity_series.html
Zn(s) + Cd*2+(aq) ==> Cd(s) + Zn^2+(aq)