Question

100克稀鹽酸恰好與80克10%的氫氧化鈉溶液完全反應(yīng)．求：
（1）稀鹽酸中溶質(zhì)的質(zhì)量分?jǐn)?shù)是多少？
（2）反應(yīng)后所得溶液中溶質(zhì)質(zhì)量分?jǐn)?shù)是多少？

Answer 1

設(shè)稀鹽酸中溶質(zhì)質(zhì)量為x，生成的氯化鈉質(zhì)量為y
反應(yīng)消耗氫氧化鈉的質(zhì)量=80g×10%=8g
NaOH+HCl═NaCl+H₂O
40  36.5  58.5
8g   x     y

40

8g

=

36.5

x

  x=7.3g   稀鹽酸中溶質(zhì)的質(zhì)量分?jǐn)?shù)=

7.3g

100g

×100%=7.3%

40

8g

=

58.5

y

  y=11.7g  反應(yīng)后所得溶液中溶質(zhì)質(zhì)量分?jǐn)?shù)=

11.7g

100g+80g

×100%=6.5%
答：（1）稀鹽酸中溶質(zhì)的質(zhì)量分?jǐn)?shù)是7.3%；（2）反應(yīng)后所得溶液中溶質(zhì)質(zhì)量分?jǐn)?shù)6.5%．