Question

Use standard reduction tables to determine which of the following species will convert Cd2+ to Cd?

Use standard reduction tables to determine which of the following species will convert Cd2+ to Cd?

A) Fe3+
B) Pb2+
C) Zn
D) Co2+
E) Sn

Answer 1

Consider the reduction of cadmium ions.

`Cd^(2+)(aq) + 2e^(-) to Cd(s)`

where, `E° = -0.40`

To reduce these ions, the metal we are oxidizing must have a reduction potential lower than cadmium.

This knowledge eliminates all but `("c")` and `("e")`.

From here, we look at our reduction potential table and notice the only metal with a standard reduction potential lower than cadmium out of these is zinc.

`E° = -0.76`