\(a) V_{rượu} = 5.\dfrac{10}{100} = 0,5(lít)\\ b) m_{rượu} = D.V = 0,78.0,5.1000 = 390(gam)\\ c) n_{C_2H_5OH\ pư} = \dfrac{380}{46}.80\% = \dfrac{156}{23}(mol)\\ C_2H_5OH + O_2 \xrightarrow{men\ giấm} CH_3COOH + H_2O\\ n_{CH_3COOH} = n_{C_2H_5OH\ pư} = \dfrac{156}{23}(mol)\\ m_{CH_3COOH} = \dfrac{156}{23}.60 = 406,96(gam)\)