Answer
$H^+(aq) + CN^-(aq) \lt -- \gt HCN(aq)$
Work Step by Step
1. Write the reaction where the reactants exchange theirs cations/anions:
$NaCN(aq) + HNO_3(aq) \lt -- \gt HCN(aq) + NaNO_3(aq)$
2. Identify the 100% dissociated/ionizated compounds, and separate them in ions:
$Na^+(aq) + CN^-(aq) + H^+(aq) + N{O_3}^-(aq) \lt -- \gt HCN(aq) + Na^+(aq) + N{O_3}^-$
Salts: Totally dissociated.
$HNO_3$: Strong acid, totally dissociated.
3. Eliminate the repeated ions/molecules:
$CN^-(aq) + H^+(aq) \lt -- \gt HCN(aq)$
- This is the net ionic equation.
