In an ammonia plant, the purge off is essential to
A
Maintain inert gas concentration within a limit
B
Remove excess poisonous gases
C
Maintain H<sub>2</sub> : N<sub>2</sub> ratio at 3 : 1
D
Remove uncondensed ammonia vapour
Correct Answer: Maintain H<sub>2</sub> : N<sub>2</sub> ratio at 3 : 1