设R的相对原子质量为X
RO+H2SO4===RS04+H20
X+16X+96
16g (16+144)X20％
求出X=64
设：稀硫酸的溶质质量分数为Y
RO + H2SO4===RS04+H20
64+16 98
16g 144Y
求出Y=13.6%