Question

欲配制100kg溶質(zhì)質(zhì)量分?jǐn)?shù)為7.1%的KNO₃溶液作無土栽培的營養(yǎng)液，需KNO₃的質(zhì)量為（ ）
A．7.1kg
B．14.2kg
C．71kg
D．92.9kg

Answer 1

【答案】分析：已知溶液質(zhì)量和溶質(zhì)質(zhì)量分?jǐn)?shù)，根據(jù)溶質(zhì)質(zhì)量=溶液質(zhì)量×溶質(zhì)質(zhì)量分?jǐn)?shù)即可求得硝酸鉀的質(zhì)量．
解答：解：配制100kg溶質(zhì)質(zhì)量分?jǐn)?shù)為7.1%的KNO₃溶液，
需KNO₃的質(zhì)量為：100kg×7.1%=7.1kg．
故選A．
點評：本題考查了溶質(zhì)質(zhì)量的計算方法；溶質(zhì)質(zhì)量=溶液質(zhì)量×溶質(zhì)質(zhì)量分?jǐn)?shù)．