For each reaction, identify the acid-base conjugate pairs. Then rank all reactions in order of increasing tendency for the reaction to go to completion (to the right).
a) CH3COO- + HCN <=> CH3COOH + CN-
b) CH3OH + Br- <=> CH3O- + HBr
c) HSO4- + NH3 <=> SO4^2- + NH4+
d) HClO4 + CH3NH2 <=> ClO4- + CH3NH3+