a) nCH3COOH bđ = 12: 60 = 0,2 (mol) ; số mol CH3COOC2H5 = 12,3 : 88 = 0,14 (mol)
PTHH: CH3COOH + C2H5OH <=> CH3COOC2H5 + H2O
b) nCH3COOH pư = nCH3COOC2H5 = 0,14 (mol)
\(\% C{H_3}COOH\,\,{\text{es}}te\,hoa = \frac{{{m_{C{H_3}CO\,OH\,pu}}}}{{{m_{C{H_3}CO\,OH\,bd}}}}.100\% \)
\(= \frac{{0,14}}{{0,2}}.100\% = 70\% \)