Which of the following reactions will occur spontaneously as written?
a) 3fe2+ (aq) + cr3+ (aq) → cr (s) + 3fe3+ (aq)
b) 2cr3+ (aq) + 3sn2+ (aq) → 3sn4+ (aq) + 2cr (s)
c) sn4+ (aq) + fe2+ (s) → sn2+ (aq) + fe (s)
d) sn2+ (aq) + fe2+ (s) → sn4+ (aq) + fe3+ (aq)
e) 2cr (s) + 3fe2+ (s) → 3fe (s) + 2cr3+ (aq)