Production of Nitric acidMuch of the nitrogen used by the chemical industry to make other raw materials is not used directly as ammonia, rather, the ammonia is first converted into nitric acid. Nitric acid production consumes about 20% of all the ammonia produced. The conversion of ammonia to nitric acid is a three-stage process: (Ⅰ) 4NH3+5O2→4NO+6H2O (Ⅱ) 2NO+O2→2NO2 (Ⅲ) 3NO2+H2O→2HNO3+NO The first reaction is catalyzed by platinum (in practice（实践中） platinum-rhodium gauze （铂－铑丝网）), as can be observed on the bench（实验台） with a piece of platinum wire and some concentrated ammonia solution. It might, at first sight（初一看）, seem that the overall reaction to the acid would be easy; unfortunately, there are complications as nature is a good deal less tidy than chemists and engineers would prefer.
Production of Nitric acidMuch of the nitrogen used by the chemical industry to make other raw materials is not used directly as ammonia, rather, the ammonia is first converted into nitric acid. Nitric acid production consumes about 20% of all the ammonia produced. The conversion of ammonia to nitric acid is a three-stage process: (Ⅰ) 4NH3+5O2→4NO+6H2O (Ⅱ) 2NO+O2→2NO2 (Ⅲ) 3NO2+H2O→2HNO3+NO The first reaction is catalyzed by platinum (in practice（实践中） platinum-rhodium gauze （铂－铑丝网）), as can be observed on the bench（实验台） with a piece of platinum wire and some concentrated ammonia solution. It might, at first sight（初一看）, seem that the overall reaction to the acid would be easy; unfortunately, there are complications as nature is a good deal less tidy than chemists and engineers would prefer.
