Question

向一定量的鹽酸中，加入硝酸銀溶液至恰好完全反應(yīng)．過(guò)濾，所得濾液的質(zhì)量等于所加硝酸銀溶液的質(zhì)量，則鹽酸中溶質(zhì)的質(zhì)量分?jǐn)?shù)為______．

Answer 1

氯化氫和硝酸銀生成氯化銀沉淀和硝酸，根據(jù)質(zhì)量守恒定律可知，鹽酸溶液的質(zhì)量和硝酸銀溶液的質(zhì)量之和等于氯化銀沉淀質(zhì)量和硝酸溶液的質(zhì)量之和，則濾液的質(zhì)量等于鹽酸溶液的質(zhì)量+硝酸銀溶液的質(zhì)量-氯化銀沉淀的質(zhì)量．又因?yàn)闉V液的質(zhì)量等于所加硝酸銀溶液的質(zhì)量，所以鹽酸的質(zhì)量=沉淀的質(zhì)量．設(shè)氯化氫的質(zhì)量是X，氯化銀的質(zhì)量是Y，則鹽酸的質(zhì)量等于沉淀的質(zhì)量．
AgNO₃+HCl═AgCl↓+HNO₃
     36.5   143.5
     X        Y

36.5

143.5

═

X

Y

得：Y=

143.5X

36.5

∴鹽酸的質(zhì)量是

143.5X

36.5

．
∴鹽酸溶液中溶質(zhì)的質(zhì)量分?jǐn)?shù)=

X

143.5X 36.5

×100%═25.4%．
故答案為：25.4%．