Question

7．向90g10%的NaCl溶液中加入10g K₂SO₄攪拌至完全溶解，所得溶液中NaCl的質(zhì)量分數(shù)為9%．

Answer 1

分析 根據(jù)溶質(zhì)質(zhì)量分數(shù)=$\frac{溶質(zhì)質(zhì)量}{溶液質(zhì)量}$×100%，進行分析解答．

解答 解：向90g10%的NaCl溶液中加入10g K₂SO₄攪拌至完全溶解，所得溶液中NaCl的質(zhì)量分數(shù)為$\frac{90g×10%}{90g+10g}$×100%=9%．
故答案為：9%．

點評 本題難度不大，掌握溶質(zhì)質(zhì)量分數(shù)=$\frac{溶質(zhì)質(zhì)量}{溶液質(zhì)量}$×100%并能靈活運用是正確解答本題的關(guān)鍵．