Robert S. answered 05/02/21
Dr Bob Loves Science (especially chemistry and math)
The balanced equation says that 3 moles of CuO will produce 1 mole of N2. That is a molar ratio of 3/1 - we only get 1 mole N2 per 3 moles CuO. . Therefore, if we start with 18 moles CuO, we'll on,ly get (1/3)*(18 moles) = 6 moles of N2. Thwe molar mass of N2 is 28 grams/mole. So convert moles N2 to grams usingf this conversion factor:
moles N 2)*(28 grams N2/ mole N 2) = 168.0 grams N2.