Question

One mole of each methonoic acid and sodium hydroxide are mixed. If x is the heat released during formation of water from $H^{+}$ and $O{H}^{-}$, the heat evolved in the above neutralization is:

• A. More than x
• B. Equal to x
• C. Less than x
• D. Twice that of x

Answer 1

The correct option is C Less than x

Methanoic acid ($HCOOH$) is a weak acid whereas $NaOH$ is a strong base. Some energy will be required for the breaking of acid into its respective ions. On reaction, salt and water will be formed.
Heat evolved in the reaction will be less than the heat evolved during formation of water from $H^{+}$ and $O{H}^{-}$.

Hence, the heat evolved on neutralisation will be less than x.