Chemistry
State how —
(i) a higher ratio of the reactant air
(ii) exothermicity of the catalytic reaction
(iii) use of low temp. in the conversion of NO to NO2 — affects each related step in Ostwald's process.
Answer
(i) Air is used in all the three main reactions of Ostwald's process i.e., the reaction in the catalytic, oxidation and absorption tower including oxidation of nitric oxide to nitrogen dioxide which requires excess of air. Hence, a higher ratio of the reactant air is used.
(ii) Since the reaction is exothermic in nature, the electrical heating is done initially only. The heat evolved i.e., heat of reaction further maintains the required temperature of the reaction.
(iii) Low temperatures are used since they :
- Facilitate easy oxidation of nitric oxide to nitrogen dioxide
- Minimize the chances of any decomposition of nitrogen dioxide which may take place at higher temperatures.
Related Questions
State which reaction of ammonia forms the first step of Ostwald's process.
Convert ammonia to nitric acid by Ostwald's process giving all conditions.
State why nitric acid
(i) stains the skin
(ii) cannot be concentrated beyond 68% by boiling.
State two conditions which affect the decomposition of nitric acid.