Question

In the industrial production of nitric acid, oxidation of ammonia with air in the presence of 90% platinum, 10% rhodium catalyst in the converter constitutes the first step, the feed gas to the converter contains around:

• A. 1 to 2% ammonia in air
• B. 10 to 12% ammonia in air
• C. 40 to 50% ammonia in air
• D. 70 to 80% ammonia in air

Hint:

In ammonia oxidation for nitric acid production, the ammonia concentration is kept low (1 to 2%) to prevent excessive heat generation during the reaction.

Answer 1

The Correct Option is A

Step 1: Understanding the oxidation process.
In the industrial production of nitric acid, the oxidation of ammonia takes place in the presence of a platinum-rhodium catalyst. The ammonia is mixed with air to initiate the reaction. The concentration of ammonia in the feed gas entering the converter is typically very low, generally between 1 and 2%, to avoid excessive heat generation and ensure a controlled reaction rate.

Step 2: Explanation of other options.
- (B) 10 to 12% ammonia is too high and would lead to a highly exothermic reaction, which is not typical in the first step. - (C) and (D) 40 to 50% or 70 to 80% ammonia would be far too concentrated for the initial oxidation reaction.

Final Answer: \[ \boxed{1 \text{ to } 2% \text{ ammonia in air}} \]