2NaOH+H2SO4==Na2SO4+2H2O
80 98
10g x
80/10g=98/x
x=12.25g
Na2CO3+H2SO4==Na2SO4+H2O+CO2↑
106 98
10g y
106/10g=98/y
y=9.25g
则稀硫酸溶质质量分数需控制的范围是9.25%----12.25%