Question

21、將50g某種硫酸溶液加入到100g溶質(zhì)質(zhì)量分?jǐn)?shù)為16%的硫酸中，充分混合后所得溶液的溶質(zhì)質(zhì)量分?jǐn)?shù)為12%，則所加硫酸的溶質(zhì)質(zhì)量分?jǐn)?shù)為（　　）

A、2%

B、4%

C、8%

D、12%

Answer 1

分析：將50g某種硫酸溶液加入到100g溶質(zhì)質(zhì)量分?jǐn)?shù)為16%的硫酸中，混合后所得溶液質(zhì)量為兩溶液的質(zhì)量和、溶液中溶質(zhì)質(zhì)量為兩溶液所含溶質(zhì)質(zhì)量和，利用溶液中溶質(zhì)質(zhì)量分?jǐn)?shù)計(jì)算公式，計(jì)算所加硫酸的溶質(zhì)質(zhì)量分?jǐn)?shù)．

解答：解：設(shè)所加硫酸的溶質(zhì)質(zhì)量分?jǐn)?shù)為x
50g×x+100g×16%=（50g+100g）×12%
x=4%
故選B．

點(diǎn)評(píng)：根據(jù)溶液組成特點(diǎn)，利用溶液的溶質(zhì)質(zhì)量分?jǐn)?shù)計(jì)算公式，解決不同質(zhì)量分?jǐn)?shù)的溶液混合問(wèn)題，正確判斷溶液的組成是解決問(wèn)題的基礎(chǔ)．