Question

29、欲配制100kg溶質(zhì)質(zhì)量分?jǐn)?shù)為7.1%的KNO₃溶液作無(wú)土栽培的營(yíng)養(yǎng)液，需KNO₃的質(zhì)量為（　�。�

A、7.1kg

B、14.2kg

C、71kg

D、92.9kg

Answer 1

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(diǎn)評(píng)：本題考查了溶質(zhì)質(zhì)量的計(jì)算方法；溶質(zhì)質(zhì)量=溶液質(zhì)量×溶質(zhì)質(zhì)量分?jǐn)?shù)．