Question

Addition of $conc.H_{2}S{O}_4$ to water is:

• A. an exothermic reaction
• B. an endothermic reaction
• C. a redox reaction
• D. neutralisation reaction

Answer 1

Answer: (A)

an exothermic reaction

The hydration reaction of sulfuric acid is highly exothermic. If water is added to concentrated sulfuric acid, it can boil and spit dangerously. One should always add the acid to the water rather than the water to the acid.

Adding $H_{2}S{O}_4$ to water releases heat, i.e., it is an exothermic reaction. First adding more acid releases more heat and the heat will be evolved because of the subsequent hydration of $H^{+}$ to $H_3{O}^{+}$ ion.

Hence, the correct option is $\text{A}$