Question

The amount of heat liberated when one mole of ${NH}_{4}OH$ reacts with one mole of $HCl$ is:

• A. $13.7kcal$
• B. More than $13.7kcal$
• C. Less than $13.67kcal$
• D. Cannot be predicted

Answer 1

The correct option is C Less than $13.67kcal$

Since, $N{H}_{4}OH$ is a weak base and $HCl$ is a strong acid so the enthalpy of reaction of $N{H}_{4}OH$ with $HCl$ will be slightly less than that of a reaction of strong acid with strong base.
Since. strong acid and strong base reacts to liberate heat = $13.7Kcal$.
Hence, for $N{H}_{4}OH$ reaction with $HCl$ heat liberated will be less than $13.7Kcal$.
Hence, answer is option C.