The equilibrium constant for the reaction ${\text{HONO}}_{\left(\text{aq}\right)}{\text{\hspace{0.17em}+\hspace{0.17em}CN}}_{\left(\text{aq}\right)}^{-}\rightleftharpoons {\text{\hspace{0.17em}HCN}}_{\left(\text{aq}\right)}{\text{\hspace{0.17em}+\hspace{0.17em}ONO}}_{\left(\text{aq}\right)}^{-}{\text{\hspace{0.17em}is\hspace{0.17em}1.1\hspace{0.17em}×10}}^{\text{6}}$.

From the magnitude of this one can conclude that

${\text{HONO\hspace{0.17em}+\hspace{0.17em}CN}}^{-}\rightleftharpoons {\text{\hspace{0.17em}HCN\hspace{0.17em}+\hspace{0.17em}ONO}}^{-}{\text{\hspace{0.17em}1.1\hspace{0.17em}×\hspace{0.17em}10}}^{\text{6}}{\text{\hspace{0.17em}indicates\hspace{0.17em}HONO\hspace{0.17em}and\hspace{0.17em}ONO}}^{-}{\text{\hspace{0.17em}:\hspace{0.17em}CN}}^{-}\text{\hspace{0.17em}\&\hspace{0.17em}HCN}$are conjugate acid base pairs ${\text{K}}_{\text{C}}$  indicates HONO is strong acid then HCN and ${\text{CN}}^{-}$ is strong base then ${\text{ONO}}^{-}$