If 64.0 g of H2O are actually obtained, find the actual yield %.

Question

Show that the % the same whether you calculate using grams or moles.

Theoretical yield is 4.04 moles and in grams is 72.80 grams
2H2 + 1O2=2H2O

Answer 1

% yield = (actual/theoretical)*100 = ?
with mols:
mols H2O in 64g is 64/18 = 3.555
%yield = (3.55/4.04)*100 = 88.0%

with grams:
%yield = (64.0/72.8)*100 = 87.91; however, if I remember this problem right the number was 72.7 g H2O (g = mols x molar mass = 4.04 x 18 = 72.7) and
(64.0/72.7)*100 = 88.0%
You get 88.0% either way.