Bạn tham khảo:
$20/$
$n_{este}=\frac{4,4}{88}=0,05(mol)$
Gọi muối là $RCOONa$
$M_{RCOONa}=\frac{4,1}{0,05}=82(g/mol)$
$R+67=82$
$R=15(CH_3)$
$\to B$
$21/$
$n_{KOH}=0,05(mol)$
$n_{ancol}=n_{RCOOK}=n_{KOH}=0,05(mol)$
$M_{ancol}=\frac{1,6}{0,05}=32(CH_3OH)$
$M_{RCOOK}=\frac{5,6}{0,05}=112$
$ \to R+83=111$
$R=29(C_2H_5)$
$ \to B$