解析 答案:62 g/mol 16 0.1 mol解析:据电离方程式Na2R===2Na++R2-,得1 mol Na2R电离生成2 mol Na+,题目中有Na+0.4 mol,则有0.2 mol Na2R.M(Na2R)==(12.4g)/(0.2mol)=62 g/mol.Mr(Na2R)=62,求得Ar(R)=62-2×23=16.已知m(R),根据n=,得n(R)=0.1 mol,则n(Na2R)=0.1 m...