Question

Match the following stages of contact process to the products formed.

• A. $2H_2{\mathrm{SO}}_4\left(\mathrm{aq}\right)$
• B. ${\mathrm{SO}}_2\left(g\right)$
• C. $H_{2}S2O_7\left(l\right)$

Answer 1

Industrial production of sulphuric acid is carried out by contact process. The different stages involved in contact process are:

Step 1. Production of sulphur dioxide$\left(S{O}_2\right)$:

$S\left(g\right)+O_2\left(g\right)\to S{O}_2\left(g\right)$
It is carried inside the burner.

Step 2. Oxidation of $S{O}_2$:

$2S{O}_2\left(g\right)+O_2\left(g\right)\stackrel{V_2{O}_5}{\to }2S{O}_3\left(g\right)$

Step 3. Absorption of $S{O}_2$ and formation of oleum $\left(H_2{S}_2{O}_7\right)$:

$S{O}_3\left(g\right)+H_{2}S{O}_4\left(aq\right)\to H_2{S}_2{O}_7\left(aq\right)$
It is carried in the absorption tower.

Step 4. Dilution of $H_{2}S{O}_4$ to produce sulphuric acid:

$H_2{S}_2{O}_7\left(aq\right)+H_{2}O\left(l\right)\to 2H_{2}S{O}_4\left(aq\right)$
It is carried in the dilution tank.