Pblock Elementsii Result Question 79
79. (a) In the following equation
$\begin{array}{r} A+2 B+\mathrm{H}_2 \mathrm{O} \longrightarrow C+2 D \\ \left(A=\mathrm{HNO}_2, B=\mathrm{H}_2 \mathrm{SO}_3, C=\mathrm{NH}_2 \mathrm{OH}\right) . \end{array}$
Identify $D$. Draw the structures of $A, B, C$ and $D$.
(b) In the contact process for industrial manufacture of sulphuric acid, some amount of sulphuric acid is used as a starting material. Explain briefly. What is the catalyst used in the oxidation of $\mathrm{SO}_2$ ?
(1999, 10M)
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Solution:
- (a)
$\underset{A}{\mathrm{HNO}_2}+\underset{B}{2 \mathrm{H}_2 \mathrm{SO}_3}+\mathrm{H}_2 \mathrm{O} \longrightarrow \underset{C}{\mathrm{NH}_2 \mathrm{OH}}+\underset{D}{2 \mathrm{H}_2 \mathrm{SO}_4}$
(b) In $\mathrm{SO}_3+\mathrm{H}_2 \mathrm{O} \longrightarrow \mathrm{H}_2 \mathrm{SO}_4$,
sulphuric acid is obtained in misty form and the reaction is explosive. By adding $\mathrm{H}_2 \mathrm{SO}_4$, above reaction is prevented :
$\begin{aligned} \mathrm{H}_2 \mathrm{SO}_4+\mathrm{SO}_3 & \longrightarrow \mathrm{H}_2 \mathrm{~S}_2 \mathrm{O}_7 \text { (oleum) } \\ \mathrm{H}_2 \mathrm{~S}_2 \mathrm{O}_7+\mathrm{H}_2 \mathrm{O} & \longrightarrow 2 \mathrm{H}_2 \mathrm{SO}_4 \end{aligned}$
In the contact process, $\mathrm{V}_2 \mathrm{O}_5$ is used as catalyst.
BETA
