Assertion : Heat of neutralisation of nitric acid with $\mathrm{NaOH}$ is same to that of $\mathrm{HCl}$ and $\mathrm{NaOH}$. Reason : In both cases strong acid and strong bases are neutralised. $\mathrm{H}^{+}+\mathrm{OH}^{-} \rightarrow \mathrm{H}_2 \mathrm{O}$

• Correct answer
  A

  If both assertion and reason are true and reason is the correct explanation of assertion
• B

  If both assertion and reason are true but reason is not the correct explanation of assertion
• C

  If assertion is true but reason is false
• D

  If both assertion and reason are false.

Hence, the correct answer is option: 'A'.