Question

                                                            

下列對20%的氯化鈉溶液的理解無錯誤的是（　�。�                      

A．該溶液中溶質(zhì)與溶劑質(zhì)量比為1：5                              

B．100g該溶液中含溶質(zhì)20g                                      

C．該溶液100g水中溶有溶質(zhì)20g                                  

D．該溶液中溶劑和溶液的質(zhì)量比為1：5                            

Answer 1

【考點】溶質(zhì)的質(zhì)量分?jǐn)?shù)；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)概念分析即可；溶質(zhì)質(zhì)量分?jǐn)?shù)=×100%．           

【解答】解：A、假設(shè)取100g20%的該溶液，溶質(zhì)的質(zhì)量=100×20%=20g，溶劑的質(zhì)量=100﹣20=80g，所以該溶液中溶質(zhì)與溶劑質(zhì)量比=20：80=1：4，故A錯；                                 

B、100g該溶液中含溶質(zhì)=100×20%=20g，故B正確；                     

C、設(shè)該溶液100g中溶有溶質(zhì)為x                                  

=20%                                                  

x=11.1g，故C錯                                             

D、由A可知該溶液中溶劑和溶液的質(zhì)量比=4：1，故D錯                 

故選：B                                                     

【點評】會靈活應(yīng)用溶質(zhì)質(zhì)量分?jǐn)?shù)的計算公式，理解透徹其含義．