nNaOH = 0,3 mol
Ch3COOH + NaOH = CH3COONa + 1/2 H2
a........................a
CH3COOC2H5 + NaOH = CH3COONa + C2H5OH
b..............................b......................................b
a+b=0,3
60a+88b=20,8
=> a=0,2   b=0,1
=> %CH3COOH = 0,2.60/20,8=57,69%
=> %CH3COOC2H5 = 42,31%
b)
nC2H5OH = b = 0,1 mol = 1/3 nNaOH
=> V rượu = 1/3 V NaOH = 100/3 ml