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Nitric acid is often manufactured from the atmospheric gases nitrogen and oxygen, and hydrogen prepared by reforming natural gas, in a two-step process. In the first step, nitrogen and hydrogen react to form ammonia: N2(g)+3H2(g)2NH3(g) In the second step, ammonia and oxygen react to form nitric acid (HNO3) and water: NH3(g)+2O2(g)HNO3(g)+H2O(g) Suppose the yield of the first step is 79.% and the yield of the second step is 82,%. Calculate the mass of hydrogen required to make 9.0kg of nitric acid. Be sure your answer has a unit symbol, if needed, and is rounded to the correct number of significant digits