【題目】化學(xué)來源于生活,圓夢中學(xué)的化學(xué)興趣小組做了以下趣味實驗:一定溫度下,

有一杯食鹽水,杯底尚有大量食鹽固體不能溶解,現(xiàn)將新鮮的蘿卜塊放入其中,放置一段時

間。小組同學(xué)分別得出了以下說法,其中說法錯誤的是

A.原食鹽水一定是飽和溶故 B.蘿卜塊質(zhì)量一定減少

C.杯中的食鹽固體一定全部溶解 D.溶液的質(zhì)量一定增加

【答案】C

【解析】

溶液的初始現(xiàn)象是有少量食鹽固體沒有溶解,說明溶液已經(jīng)是飽和狀態(tài),A選項正

確;將新鮮的蘿卜放入食鹽水中,我們能看到蘿卜會萎縮的現(xiàn)象,因為蘿卜體內(nèi)的

水分會進入食鹽溶液中,因此蘿卜塊質(zhì)量減少而溶液的質(zhì)量增加,選項BD正確。

因為進入溶液的水量很小,能不能將未溶解的氯化鈉全部溶解不一定,所以C選項

錯誤。

知識點:溶液狀態(tài)及常識。

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