Answer
See explanation below.
Work Step by Step
Oxidation: Co(s) --> Co2+(aq) + 2 e- -E° = 0.28 V
Reduction: 2 H+(aq) + 2 e- --> H2(g) E° = 0.00 V
Total complete reaction: Co(s) + 2 H+(aq) --> Co2+(aq) + H2(g) E cell = 0.28 V
Reaction is spontaneous as E cell is positive