Question

t°C時，分別將ag下列物質(zhì)投入bg水中，使其完全溶解，則下列說法中不正確的是（　　）
①硝酸鉀    ②氯化鈉    ③三氧化硫    ④碳酸鈉晶體．

A．③溶液中溶質(zhì)質(zhì)量分數(shù)最大

B．①、②溶液中溶質(zhì)質(zhì)量分數(shù)相等

C．③、④溶液中溶質(zhì)質(zhì)量分數(shù)相等

D．④比①溶液中溶質(zhì)的質(zhì)量分數(shù)大

Answer 1

根據(jù)將ag物質(zhì)投入bg水中使其完全溶解，可得知完全溶解后所得的四種溶液的質(zhì)量相等；由于③三氧化硫能與水發(fā)生反應(yīng)生成硫酸，而使所得溶液中溶質(zhì)質(zhì)量大于ag；④碳酸鈉晶體帶一定量的結(jié)晶水，而使所得溶液中溶質(zhì)質(zhì)量小于ag；①硝酸鉀和②氯化鈉兩種物質(zhì)完全溶解后所得溶液中溶質(zhì)質(zhì)量仍為ag；
利用溶液的溶質(zhì)質(zhì)量分數(shù)=

溶質(zhì)質(zhì)量

溶液質(zhì)量

×100%，溶液質(zhì)量相等時，溶質(zhì)質(zhì)量大，則溶液的溶質(zhì)質(zhì)量分數(shù)也大；溶質(zhì)質(zhì)量小，則溶液的溶質(zhì)質(zhì)量分數(shù)也小；可得以下結(jié)論：③溶液中溶質(zhì)質(zhì)量分數(shù)最大，故A正確；①、②溶液中溶質(zhì)質(zhì)量分數(shù)相等，故B正確；③溶液中溶質(zhì)質(zhì)量分數(shù)大于④，故C不正確；④比①溶液中溶質(zhì)的質(zhì)量分數(shù)�。还蔇不正確；
故選C、D．