The first step in the manufacture of nitric acid by the Ostwald process is the reaction of ammonia gas with oxygen, producing nitrogen oxide and steam. The reaction mixture contains 8.69 g of ammonia and 10.4 g of oxygen. After the reaction is complete, 6.70 g of nitrogen oxide are obtained. Write a balanced equation for the reaction. How many grams of nitrogen oxide can be theoretically obtained? How many grams of excess reactant are theoretically unused? What is the percent yield of the reaction?