Question

現(xiàn)有10%的食鹽溶液100g，若要使溶液的溶質(zhì)質(zhì)量分?jǐn)?shù)增加一倍，應(yīng)向此溶液中加入多少食鹽？

Answer 1

分析：根據(jù)溶質(zhì)的質(zhì)量分?jǐn)?shù)=

溶質(zhì)質(zhì)量

溶液質(zhì)量

×100%，溶質(zhì)質(zhì)量=溶質(zhì)質(zhì)量=溶液質(zhì)量×溶質(zhì)的質(zhì)量分?jǐn)?shù)，結(jié)合題意進(jìn)行分析解答即可．

解答：解：現(xiàn)有10%的食鹽溶液100g，若要使溶液的溶質(zhì)質(zhì)量分?jǐn)?shù)增加一倍，
設(shè)應(yīng)向此溶液中加入食鹽的質(zhì)量為x，
則100g×10%+x=（100g+x）×20%
x=12.5g
答：應(yīng)向此溶液中加12.5g食鹽．

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