Answer to Question #85957 in General Chemistry for thomas

Question

Hydrocyanic acid, HCN, is a weak acid. Write a net ionic equation for the reaction of aqueous hydrocyanic acid and aqueous sodium hydroxide.

A. HCN(aq) + Na+(aq) + OH-(aq) → Na+(aq) + CN–(aq) + H2O()
B. HCN(aq) + OH–(aq) → CN–(aq) + H2O()
C. H+(aq) + OH–(aq) → H2O()
D. NaOH(aq) → Na+(aq) + OH-(aq)
E. HCN(aq) + H2O(aq) → CN–(aq) + H3O+(aq)

Answer 1

B. HCN(aq) + OH^-(aq) ---> H2O(l) + CN^-(aq)

HCN is written in the molecular way since it is a weak acid and ionizes only a small amount. NaOH, on the other hand, is a strong electrolyte, ionizing 100% in solution. The Na^+ is a spectator ion, so it is not written in the net ionic equation.