Ответ:
CH3COOH + CH3CH2OH = CH3COOCH2CH3 + H2O
mтеоретич.(CH3COOCH2CH3) = mпракт./wвыхода = 118,8/0,9 = 132 г
n(CH3COOCH2CH3) = m(CH3COOCH2CH3)/M(CH3COOCH2CH3) = 132/88 = 1.5моль
n(CH3COOCH2CH3) = n(CH3COOH) = 1.5 моль
m(CH3COOH) = n(CH3COOH)*M(CH3COOH) = 1.5*60 = 90г