Question

The number of steps involved in the manufacturing of nitric acid through Ostwald's process is:

• A. 1
• B. 5
• C. 3
• D. 6

Answer 1

The correct option is C 3

Ostwald process to manufacture nitric acid-

Step $1$: Catalytic oxidation of Ammonia

A mixture of dry air and dry ammonia in the ratio of $10:1$ by volume is compressed and then passed into a platinum gauze which acts as catalyst at about $800℃$.

$4N{H}_3+5O_2⟶4NO+6H_{2}O+\text{Heat}$

Step $2$: Oxidation of nitric oxide

Nitric oxide combines with oxygen to form nitrogen dioxide at about 50°C.

$2NO+O_2⟶2N{O}_2$

Step $3$: Absorption of nitrogen dioxide in water

The nitrogen dioxide and oxygen present in the air react with water to form nitric acid.

$4N{O}_2+2H_{2}O+O_2⟶\underset{\text{Nitric acid}}{4HN{O}_3}$

Nitric acid obtained is concentrated above $50\%$. On further distillation, $68\%$ nitric acid is produced.
Hence, the number of steps involved in the manufacturing of nitric acid is 3.