Question

取70g某溫度下的氯化鉀飽和溶液，將其恒溫蒸發(fā)l0g水，析出4g氯化鉀固體，則剩余溶液中所含溶質(zhì)的質(zhì)量分?jǐn)?shù)為（　�。�

A．40%

B．28.6%

C．6.7%

D．7.1%

Answer 1

由題意得溶液的恒溫蒸發(fā)時(shí)蒸發(fā)的溶劑與析出的溶質(zhì)正好配置成這一溫度下的飽和溶液，所剩溶液也飽和，故溶質(zhì)質(zhì)量分?jǐn)?shù)相同，則剩余溶液中所含溶質(zhì)的質(zhì)量分?jǐn)?shù)為

4g

10g+4g

×100%=28.6%
故選B