ms = ro×V = 1,1×200 = 220g C6H12O6
C = md/ms×100 => md = C×ms/100 = 10×220/100 = 22g C6H12O6
n = V/Vm = 4/22,4 = 0,178 moli CO2
C6H12O6 --> 2C2H5-OH + 2CO2
180g C6H12O6.......................2 moli CO2
xg C6H12O6.............................0,178 moli
x = 16g
%u = 16/22×100 = 73