Question

The heat of neutralization of a strong base and a strong acid is $13.7\, kcal.$ The heat released when $0.6$ mole $HCl$ solution is added to $0.25$ mole of $NaOH$ is

• A. 3.425 kcal
• B. 8.22 kcal
• C. 11.645 kcal
• D. 13.7 kcal

Answer 1

Answer: (A)

Given, the heat of neutralisation of a strong base and a strong acid is $13.7 \,kcal$.

The reátion of neutralisation is as follows

$\underset{\text{1 mol}}{{HCl}}+\underset{\text{1 mol}}{{NaOH}} \to NaCl+H_2O ; \Delta\,H =13.7\,kcal$

According to question,

$\underset{\text{0.6 mol}}{{HCl}}+\underset{\text{0.25 mol}}{{NaOH}} \to NaCl +H_2O \,\,\,\,\,\dots(i)$

In equation (i), $NaOH$ acts as a limiting reagent. For 1 mole of $NaOH$ and 1 mole of $HCl$, heat of neutralisation $=13.7\, kcal $

$\therefore $ For $0.25$ mole of $NaOH$ and $0.6$ mole of $HCl$, heat of neutralisation $=13.7 \times 0.25$

$ \Rightarrow 3.425 \,kcal$