Question

向20g溶質(zhì)質(zhì)量分?jǐn)?shù)為4%的氯化鈉溶液中，加入40g溶質(zhì)質(zhì)量分?jǐn)?shù)為10%的該溶液，求所得溶液的溶質(zhì)質(zhì)量分?jǐn)?shù)．

Answer 1

考點(diǎn)：有關(guān)溶質(zhì)質(zhì)量分?jǐn)?shù)的簡單計算

專題：溶液的組成及溶質(zhì)質(zhì)量分?jǐn)?shù)的計算

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%，溶質(zhì)質(zhì)量=溶液質(zhì)量×溶質(zhì)的質(zhì)量分?jǐn)?shù)，進(jìn)行分析解答．

解答：解：原溶液中的溶質(zhì)的質(zhì)量為：20g×4%=0.8g．
新加入溶液中溶質(zhì)的質(zhì)量為：40g×10%=4g，
則所得溶液的溶質(zhì)質(zhì)量分?jǐn)?shù)為：

0.8g+4g

20g+40g

×100%=8%．
答：所得溶液的溶質(zhì)質(zhì)量分?jǐn)?shù)為8%．

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