`150 mL` of `0.5N` nitric acid solution at `25.35^(@)C` was mixed with `150 mL` of `0.5 N` sodium hydroxide solution at the same temperature. The final temperature was recorded to be `28.77^(@)C`. Calculate the heat of neutralisation of nitric acid with sodium hydroxide.

Explanation

Total mass of solution `=150+150=300g`
Q=total heat produced `=300xx(28.77-25.35)cal`
`=300xx3.42=1026cal`
Heat of neutralisation `=(Q)/(150)xx1000xx(1)/(0.5)`
`=(1026)/(150)xx1000xx(1)/(0.5)=13.68kcal`
Since, heat is liberated, heat of neutralisation should be negative.
so, heat neutralisation `=-13.68kcal`