由圖可知25g的石灰石和鹽酸充分反應(yīng)生成CO₂的質(zhì)量為8.8g
設(shè)石灰石中CaCO₃的質(zhì)量為x，反應(yīng)后生成CaCl₂的質(zhì)量為y
CaCO₃+2HCl═CaCl₂+H₂O+CO₂↑
100          111      44
 x            y      8.8g

100

x

=

44

8.8g

  x=20g

111

y

=

44

8.8g

  y=22.2g
石灰石中碳酸鈣的質(zhì)量分?jǐn)?shù)=

20g

25g

×100%=80%
所得溶液中溶質(zhì)的質(zhì)量分?jǐn)?shù)=

22.2g

20g+146g?8.8g

×100%≈14.1%
答：①石灰石中碳酸鈣的質(zhì)量分?jǐn)?shù)為80%；②當(dāng)二者恰好完全反應(yīng)時(shí)，所得溶液中溶質(zhì)的質(zhì)量分?jǐn)?shù)為14.1%．