Using the given data, determine the pair of substances that will react spontaneously.
2H+ (aq) + 2e- →H2 (g) E=0.00 V
Sn2+ (aq) + 2e (aq) + 2e → Sn (s) E=-0.15 V
Cd2+ (aq) + 2e→ Cd (s)