Question

在農(nóng)村，有時(shí)用10%～20%的氯化鈉溶液來(lái)選種．若要配制55kg15%的氯化鈉溶液，需要

 

kg氯化鈉，

 

kg水．

Answer 1

考點(diǎn)：有關(guān)溶質(zhì)質(zhì)量分?jǐn)?shù)的簡(jiǎn)單計(jì)算

專(zhuān)題：溶液的組成及溶質(zhì)質(zhì)量分?jǐn)?shù)的計(jì)算

分析：利用溶質(zhì)質(zhì)量=溶液質(zhì)量×溶質(zhì)的質(zhì)量分?jǐn)?shù)，可根據(jù)溶液的質(zhì)量和溶質(zhì)的質(zhì)量分?jǐn)?shù)計(jì)算配制溶液所需要的溶質(zhì)的質(zhì)量；再根據(jù)溶劑質(zhì)量=溶液質(zhì)量-溶質(zhì)質(zhì)量即可求得水的質(zhì)量．

解答：解：溶質(zhì)質(zhì)量=溶液質(zhì)量×溶質(zhì)的質(zhì)量分?jǐn)?shù)，要配制55kg15%的氯化鈉溶液，需要氯化鈉的質(zhì)量為55kg×15%=8.25kg；溶劑質(zhì)量=溶液質(zhì)量-溶質(zhì)質(zhì)量，則需要水的質(zhì)量為55kg-8.25kg=46.75kg．
故答案為：8.25；46.75．

點(diǎn)評(píng)：本題難度不大，掌握溶質(zhì)質(zhì)量=溶液質(zhì)量×溶質(zhì)的質(zhì)量分?jǐn)?shù)、溶劑質(zhì)量=溶液質(zhì)量-溶質(zhì)質(zhì)量是正確解答的關(guān)鍵．