Question

在80g質(zhì)量分?jǐn)?shù)為15%硝酸鈉溶液里加入20g水或再溶解20g硝酸鈉，則兩種溶液中溶質(zhì)質(zhì)量分?jǐn)?shù)分別為    和    ．

Answer 1

【答案】分析：根據(jù)溶質(zhì)的質(zhì)量分?jǐn)?shù)=×100%進(jìn)行解答．
解答：解：在80g質(zhì)量分?jǐn)?shù)為15%硝酸鈉溶液里加入20g水后溶質(zhì)的質(zhì)量分?jǐn)?shù)是：×100%=12%；
  在80g質(zhì)量分?jǐn)?shù)為15%硝酸鈉溶液里再溶解20g硝酸鈉后溶質(zhì)的質(zhì)量分?jǐn)?shù)是：×100%=32%；
故答案為：12%；32%．
點(diǎn)評(píng)：了解溶質(zhì)質(zhì)量分?jǐn)?shù)的計(jì)算方法，并能根據(jù)題意靈活分析解答即可．