题目

下列离子反应方程式正确的是 ①碳酸氢钙溶液与过量烧碱溶液混合：Ca2++HCO3−+OH−错误！未找到引用源。CaCO3+H2O ②碳酸镁与稀硫酸：MgCO3+2H+错误！未找到引用源。H2O+CO2↑+Mg2+ ③醋酸与大理石：2CH3COOH+CaCO3错误！未找到引用源。Ca2++2CH3COO−+H2O+CO2↑ ④向NaHSO4溶液中逐滴加入Ba(OH)2溶液至SO42﹣刚好沉淀完全： H++SO42−+Ba2++OH−错误！未找到引用源。H2O+BaSO4↓ ⑤向Na2SiO3溶液中滴加稀盐酸：Na2SiO3＋2H＋错误！未找到引用源。H2SiO3↓＋2 Na+ ⑥Fe2+与H2O2在酸性溶21、Hoping to be stronger to compete with the world’s best, Murray has put on about 4kg by eating twice as much as his         amount. A．common         B．ordinary           C．formal           D．usual