Question

將50溶質(zhì)質(zhì)量分?jǐn)?shù)為8%的硝酸鉀溶液，恒溫蒸發(fā)25g水，沒有晶體析出，求所得溶液的溶質(zhì)質(zhì)量分?jǐn)?shù)．

Answer 1

考點：用水稀釋改變濃度的方法

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%，結(jié)合題意進(jìn)行分析解答即可．

解答：解：現(xiàn)有溶質(zhì)的質(zhì)量分?jǐn)?shù)為8%的KNO₃溶液50g，現(xiàn)在將該溶液恒溫蒸發(fā)掉25g水后，所得溶液的溶質(zhì)質(zhì)量分?jǐn)?shù)是

50g×8%

50g-25g

×100%=16%．
答：所得溶液的溶質(zhì)質(zhì)量分?jǐn)?shù)是16%．

點評：本題難度不大，掌握溶質(zhì)質(zhì)量分?jǐn)?shù)的有關(guān)計算并能靈活運用即可正確解答本題．