1、酸碱中和反应2、CH3COOH+NaON=CH3COONa+H2O 60 g 40 g X g 25x4% g 即60x25x4%=40X 解之得X=1.5 白醋中醋酸的质量分数为:(1.5g/30g)x100%=5%