解：由圖可知，參加反應(yīng)的碳酸鈣的質(zhì)量為?$12\mathrm {g}-2\mathrm {g}=10\mathrm {g}$?
設(shè)反應(yīng)結(jié)束時(shí)生成二氧化碳?xì)怏w的質(zhì)量為?$x。$?
?$\mathrm {CaCO}_3+2\mathrm {HCl}\xlongequal[ ]{ }\mathrm {CaCl}_2+\mathrm {H}_2\mathrm {O}+\mathrm {CO}_2↑$?
100 44
10g ?$x$?
?$\frac {100 }{44 }=\frac {10\mathrm {g} }{x }，$?解得?$x=4.4\mathrm {g}$?
答：反應(yīng)結(jié)束時(shí)生成二氧化碳的質(zhì)量為?$4.4\mathrm {g}。$?
