Question

為有效地預(yù)防非典型肺炎，我省各中小學(xué)校實(shí)行天天消毒制度．某校如果用質(zhì)量分?jǐn)?shù)為l O%的“白貓消毒液”，配制1 0kg質(zhì)量．分?jǐn)?shù)為O．25%的稀消毒液，需用1O%的“白貓消毒液”

O.25kg

 kg．

Answer 1

分析：配制過程中溶質(zhì)質(zhì)量不變；由稀溶液的溶液質(zhì)量和溶質(zhì)質(zhì)量分?jǐn)?shù)可以計算出溶質(zhì)質(zhì)量，由溶質(zhì)質(zhì)量和濃溶液的溶質(zhì)質(zhì)量分?jǐn)?shù)可以計算出濃溶液的質(zhì)量．

解答：解：需用1O%的“白貓消毒液”的質(zhì)量為x，則
x×10%=10kg×0.25%
解得，x=0.25Kg
答：需用1O%的“白貓消毒液”O(jiān).25kg．

點(diǎn)評：本題主要考查溶質(zhì)質(zhì)量分?jǐn)?shù)的計算、一定溶質(zhì)質(zhì)量分?jǐn)?shù)的溶液的配置，難度較�。�