A: C2H5OH
B: CH3COOC2H5
C: (CH3COO)2Ca
D : CH3COONa
\(C_2H_5OH + O_2 \xrightarrow{t^o,xt} CH_3COOH + H_2O\\ CH_3COOH + C_2H_5OH \rightleftharpoons CH_3COOC_2H_5 + H_2O\\ CH_3COOC_2H_5 + NaOH \to CH_3COONa + C_2H_5OH\\ 2CH_3COOH + Ca \to (CH_3COO)_2Ca + H_2\\ (CH_3COO)_2Ca + Na_2CO_3 \to 2CH_3COONa + CaCO_3\\ CH_3COONa + HCl \to CH_3COOH + NaCl\)