2H2 + O2 --->2H2O
from equation 2 mol 2 mol
given 4 mol 3 mol
How much
we could get
using 4 mol of H2. 4 mol x mol
2 mol H2 gives 2 mol H2O, 4 mol H2 could give 4 mol H2O.
So, 4 mol H2O is theoretical yield.
% yield = (actual yield/theoretical yield)*100% = (3 mol/4 mol)*100% = 75 %
Answer is C. 75%.