Identify the two conjugate acid-base pairs in each of the following:

Question

A) H2PO4^-(aq) + HSO4^-(aq) = H3PO4(aq) + SO4^2-(aq)

B) HI(aq) + CN^-(aq) = HCN(aq) + I^-(aq)

i got
a) H2PO4^- , HSO4^- and SO4^2-
b) CN^- and I^-
But i don't think that these are right, please help!

Answer 1

The question asks for PAIRS (meaning it want a pair for each).
A is H2PO4^-/H3PO4; and HSO4^-/SO4^2-
B is HI/I^-; and CN^-/HCN
Note: for B, CN^- is the base and HCN is the conjugate acid while HI is an acid and I^- is the conjugate base.