Question

Which of the following is the acidic anhydride for sulphuric acid?

• A. Sulphur dioxide
• B. Dinitrogen pentoxide
• C. Sulphur trioxide
• D. Sulphur

Answer 1

The correct option is C Sulphur trioxide

Sulphur dioxide $\left(S{O}_2\right)$ is the acidic anhydride form of sulphurous acid $\left(H_{2}S{O}_3\right)$. Dinitrogen pentoxide $\left(N_2{O}_5\right)$ is the acidic anhydride form of nitric acid $\left(HN{O}_3\right)$. Sulphur trioxide $\left(S{O}_3\right)$ is the acidic anhydride form of sulphuric acid $\left(H_{2}S{O}_4\right)$. Sulphur is not an acidic anhydride.