100g*5%=5g
(1)蒸發(fā)10g水后,溶質(zhì)的質(zhì)量分?jǐn)?shù)為 5g/(100g-10g)*100%=5.56%
(2)增加10gNaCl后,溶質(zhì)的質(zhì)量分?jǐn)?shù)為 (5g+10g)/(100g+10g)*100%= 13.64%
(3)增加10gNaCl和10GH2O后,溶質(zhì)的質(zhì)量分?jǐn)?shù)為(5g+10g)/(100g+10g+10g)*100%=12.5%
(4)加入100g15%的NaCl溶液后,溶質(zhì)的質(zhì)量分?jǐn)?shù)為(5g+100g*15%)/(100g+100g)*100%=10%