解：設(shè)消耗?$\mathrm {Na}_2\mathrm {CO}_3$?的質(zhì)量為?$x。$?
?$\mathrm {Na}_2\mathrm {CO}_3+\mathrm {CaCl}_2\xlongequal[ ]{ }2 \mathrm {NaCl}+\mathrm {CaCO}_3↓$?
106 100
?$x$? 4g
?$\frac {106 }{100 }=\frac {x }{4\mathrm {g} }，$?解得?$x=4.24\mathrm {g}$?
答：僅生成?$4\mathrm {g}$?沉淀所消耗?$\mathrm {Na}_2\mathrm {CO}_3$?固體的質(zhì)量為?$4.24\mathrm {g}。$?
