醋酸与氢氧化镁反应生成易溶性醋酸镁和水，离子方程式为：Mg（OH）2+2CH3COOH=Mg2++2CH3COO-+2H2O，故答案为：Mg（OH）2+2CH3COOH=Mg2++2CH3COO-+2H2O．
