Answer:
HCN + NO₂⁻ ⇌ CN⁻ + HNO₂
Weak acid Strong base Conj. strong base Conj. weak acid
Explanation:
In the Bronsted-Lowry theory we identify the acids as the compounds that can release protons and the bases, the compounds that can accept them.
For example:
HCl → It can release the proton → Acid → Hydrochloric acid
NH₃ → It can accept a proton → Base → Ammonia
The equation is:
HCN + NO₂⁻ ⇌ CN⁻ + HNO₂
Cianhydric acid release a proton (acid) to the nitrite (base).
Nitrite can accept the proton (base) to become nitrous acid.
Then, the cianide can also accept the proton (base) to become cianhydric acid, again.
