Question

4NH3 + 7O2 --> 4NO2 + 6H20

1) How many grams of oxygen are necessary to produce 4.50 moles of NO2?

2) How many molecules of water are produced when 2.25 moles of ammonia are completely reacted?

Answer 1

1.Convert 4.5 mol NO2 to mols oxygen using the coefficients in the balanced equation.
Convert mols oxygen to grams oxygen. grams oxygen = mols oxygen x molar mass oxygen.

2. Convert 2.25 mols NH3 to mols H2O using the coefficients of the equation.
Convert mols H2O to molecules H2O remembering that 1 mol contains 6.02 x 10^23 molecules.