(1).计算需要加入的硝酸钾质量克数m
(160g*20%+m)/(160g+m)=25%
32g+m=40g+0.25m
0.75m=8g
m=10.7g
(2).计算混合溶液的浓度质量分数
(160g*20%+40g*30%)/(160g+40g)
=(32g+12g)/200g
=22g/100g
=22% .
(1).计算需要加入的硝酸钾质量克数m
(160g*20%+m)/(160g+m)=25%
32g+m=40g+0.25m
0.75m=8g
m=10.7g
(2).计算混合溶液的浓度质量分数
(160g*20%+40g*30%)/(160g+40g)
=(32g+12g)/200g
=22g/100g
=22% .