Question

一份溶質(zhì)的質(zhì)量分?jǐn)?shù)為2%的氯化鈉溶液蒸發(fā)掉40g水后，其溶質(zhì)的質(zhì)量分?jǐn)?shù)變?yōu)閘0%，則原溶液中溶質(zhì)的質(zhì)量為（　�。�

Answer 1

分析：根據(jù)溶質(zhì)質(zhì)量分?jǐn)?shù)=

溶質(zhì)質(zhì)量

溶液質(zhì)量

×100%，結(jié)合題意進(jìn)行分析解答．

解答：解：一份溶質(zhì)的質(zhì)量分?jǐn)?shù)為2%的氯化鈉溶液蒸發(fā)掉40g水后，其溶質(zhì)的質(zhì)量分?jǐn)?shù)變?yōu)閘0%，設(shè)原溶液的質(zhì)量為x，則

2%x

x-40g

×100%=10%     x=50g
則原溶液中溶質(zhì)的質(zhì)量為50g×2%=1g．
故選A．

點(diǎn)評(píng)：本題難度不大，掌握溶質(zhì)質(zhì)量分?jǐn)?shù)的有關(guān)計(jì)算并能靈活運(yùn)用是正確解答本題的關(guān)鍵．