Consider the following reactions. Which do you predict will occur most rapidly at room conditions? Slowest?

a)

C2H6 (g) + O2 (g) → 2 CO2 (g) + 3 H2O(g)

b) Fe(s) + O2 (g) → Fe2O3 (s)

c) H2O(l) + CO2 (g) → H2CO3 (g)

d) 2 Fe3+(aq) + Sn2+(aq) → 2 Fe2+(aq) + Sn4+(aq)