Question

The starting material in Birkeland and Eyde process for manufacture of nitric acid is:

• A. ammonia
• B. $N{O}_2$ gas
• C. air
• D. Chile saltpetre

Answer 1

The correct option is C air

The Birkeland–Eyde process was one of the competing industrial processes at the beginning of nitrogen-based fertilizer production

This process was used to fix atmospheric nitrogen $\left(N\right)$ into nitric acid $\left(HN{O}_3\right)$, one of several chemical processes generally referred to as nitrogen fixation. The resultant nitric acid was then used as a source of nitrate $\left(N{O}^{-}\right)$ in the reaction

$HNO\to H^{+}+N{O}^{-}$

Thus here nitrogen and oxygen from air are used as a starting material.