In the first step of the Ostwald process for the manufacture of nitric acid, ammonia is oxidized catalytically to give nitric oxide ( NO ) and water. The number of moles of oxygen gas ( O₂ ) required to produce 20 moles of nitric oxide is:

Step-by-step solution

The balanced chemical equation for the catalytic oxidation of ammonia in the Ostwald process is: 4NH₃(g) + 5O₂(g) 4NO(g) + 6H₂O(g) According to the stoichiometry of the reaction, 4 moles of NO are produced by the reaction of 5 moles of O₂ . Therefore, 1 mole of NO requires 5 4 moles of O₂ . To produce 20 moles of NO , the number of moles of O₂ required is: Moles of O₂ = 5 4 20 = 25 moles. Thus, 25 moles of oxygen gas are required. Answer: 25