Question

醫(yī)院要配制200克質(zhì)量分?jǐn)?shù)為2%的碘酒用來消毒，需要碘

 

克；酒精

 

毫升．（酒精的密度為0.8g/cm³）

Answer 1

考點：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：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)量即可求得酒精的質(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)，醫(yī)院要配制200克質(zhì)量分?jǐn)?shù)為2%的碘酒用來消毒，需碘的質(zhì)量=200g×2%=4g；溶劑質(zhì)量=溶液質(zhì)量-溶質(zhì)質(zhì)量，則所需酒精的質(zhì)量=200g-5g=196g；酒精的密度為0.8g/cm³，根據(jù)V=

m

ρ

=

196g

0.8g/cm3

=245cm³=245mL．
故答案為：4；245．

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(yùn)用是正確解答本題的關(guān)鍵．