Question

生產(chǎn)燒堿的工廠，常用便宜的原料純堿和熟石灰制得成品．為模擬該生產(chǎn)過程，同學(xué)們?nèi)?0gNa₂CO₃溶液與一定質(zhì)量的飽和石灰水混合，恰好完全反應(yīng)，得到4g白色沉淀．求Na₂CO₃溶液中溶質(zhì)的質(zhì)量分?jǐn)?shù)．

Answer 1

設(shè)20g碳酸鈉溶液中碳酸鈉的質(zhì)量為x
Na₂CO₃+Ca（OH）₂=CaCO₃↓+2NaOH
106             100
x               4g

106

100

=

x

4g

x=

106×4g

100

=4.24g
碳酸鈉溶液中溶質(zhì)的質(zhì)量分?jǐn)?shù)為

4.24g

20g

×100%=21.2%
答：碳酸鈉溶液中溶質(zhì)的質(zhì)量分?jǐn)?shù)為21.2%