NEETChemistryp Block Elements (Group 15, 16, 17 & 18)
In the industrial manufacture of nitric acid by the Ostwald process, the final chemical step involves the absorption of nitrogen dioxide gas in water to yield aqueous nitric acid. Which gaseous byproduct is generated during this absorption step, and what is its subsequent fate in the industrial plant?
Options
- AN₂O , which is released into the atmosphere
- BNO₂ , which is recycled back into the absorption tower
- CNO , which is further oxidized to N₂O₅
- DNO , which is recycled and oxidized to NO₂
Correct answer
D. NO , which is recycled and oxidized to NO₂
Step-by-step solution
The third step of the Ostwald process is the absorption of nitrogen dioxide in water to form nitric acid. The balanced chemical equation for this step is: 3 NO₂ ( g ) + H₂O ( l ) 2 HNO₃ ( aq ) + NO ( g ) The gaseous byproduct generated is nitric oxide ( NO ). In the industrial plant, this NO is not wasted; it is recycled back into the second step of the process where it is oxidized by air to form more NO₂ ( 2 NO + O₂ 2 NO₂ ). Answer: NO , which is recycled and oxidized to NO₂