JEE Main 2021 · 20 July · evening · Single correct · +4 / −1
The single largest industrial application of dihydrogen is :
- (a) Manufacture of metal hybrides
- (b) Rocket fuel in space research
- (c) In the synthesis of ammonia
- (d) In the synthesis of nitric acid
Answer and solution
Answer (c) In the synthesis of ammonia
Solution
Chemistry ma’am · 3 steps
Think of what the world makes in the largest tonnage from H₂: ammonia by the Haber process.
- Where hydrogen goes. Most dihydrogen produced in industry is used up in one reaction: combining it with nitrogen to make ammonia. That ammonia is needed in huge quantities for fertilisers.
N₂(g) + 3H₂(g) ⇌(Fe, 700 K, 200 atm) 2NH₃(g)
- The other uses. Dihydrogen is also used to hydrogenate vegetable oils, to make methanol and metal hydrides, and as rocket fuel. Each of these uses far less than ammonia synthesis does.
- So. The single largest industrial use of dihydrogen is the synthesis of ammonia, option (c).
The idea to keep. Hydrogen's biggest job is the Haber process. Nitric acid and fertilisers come later, from that ammonia, so they are downstream uses and not the direct one.
Answer from the NTA final answer key. Solution by PrepWiser.