Q$20$ Given:

$K_{a}ofHF=6\mathrm{.}8{10}^{-4}$

$K_{a}ofN{H}_4^{+}=6\mathrm{.}3{10}^{-10}$

$K_{a}ofHCN=4\mathrm{.}9{10}^{-10}$

According to the given data above, a $0\mathrm{.}10M$ solution of which of the following would have the

highest $pH?$

NaF,NaCN,$N{H}_{4}Cl,N{H}_{4}F,N{H}_{4}CN$