Nitric oxide (NO) is made from the oxidation of NH3 according to the equation 4 NH3 + 5 O2 → 4 NO + 6 H2O . If an 13.97 g sample of NH3 gives 22.6 g of NO, what is the percent yield?

Answer 1

4NH₃ + 5O₂ ==> 4NO + 6H₂O ... balanced equation

Assuming that O₂ is present in excess, we proceed as follows:

moles NH₃ used = 13.97 g NH₃ x 1 mol NH₃/17.031 g = 0.8203 moles NH₃

mass NO expected (theoretical yield) = 0.8203 mol NH₃ x 4 mol NO/4 mol NH₃ x 30.01 g/mol = 31.178 g NO

Percent yield = actual yield/theoretical yield (x100%) = 22.6 g/31.178 g (x100%) = 72.5% yield