Question

In the preparation of $HN{O_3}$ we get $NO$ gas by catalytic oxidation of ammonia. The moles of NO produced by the oxidation of two moles of $N{H_3}$ will be:
(A) 2
(B) 3
(C) 4
(D) 6

Answer 1

Hint : The formation of nitric acid from ammonia is called Ostwald’s process and 4 moles of ammonia produces four moles of nitric oxide. After balancing the reaction, we will find the number of moles of NO produced by the oxidation of two moles of $N{H_3}$ .

Complete Step By Step Answer:
The chemical process for the formation of Nitric acid or $HNO3$ is also called the Ostwald process. This process was developed by Wilhelm Ostwald in 1902. This is a very important process as it produces the main raw material for most common types of fertilizer production.
Ammonia is converted to nitric acid in two stages. First it is oxidized by heating with oxygen in the presence of a catalyst such as platinum with 10 percent rhodium, platinum metal on fused silica wool, copper or nickel to form nitric oxide and water. This is a strongly exothermic reaction making it a useful heat source once initiated. The reaction is given as follows:
$4N{H_3}(g) + 5{O_2}(g)\xrightarrow{{}}4NO(g) + 6{H_2}O$
This reaction is for four moles of ammonia. So, the reaction for 2 moles of ammonia is as given below:
$2N{H_3}(g) + \dfrac{5}{2}{O_2}(g)\xrightarrow{{}}2NO(g) + 3{H_2}O$
Therefore, 2 moles of $NO$ are produced. So, the correct option is A.

Note :
Here we noted about the Ostwald’s process which is an important process for the formation of nitric acid from ammonia. Nitric acid is also known as aqua fortis from Latin word meaning “Strong water”. It is a highly corrosive mineral acid. The pure compound is colourless but older samples tend to acquire a yellow cast due to decomposition into oxides of nitrogen and water.