Question

9．將質(zhì)量分?jǐn)?shù)為98%的濃H₂SO₄100g溶于400g水中，求稀硫酸中H₂SO₄的質(zhì)量分?jǐn)?shù)．

Answer 1

分析 利用溶質(zhì)質(zhì)量=溶液質(zhì)量×溶質(zhì)的質(zhì)量分?jǐn)?shù)，結(jié)合溶質(zhì)質(zhì)量分?jǐn)?shù)=$\frac{溶質(zhì)質(zhì)量}{溶液質(zhì)量}$×100%，進(jìn)行分析解答即可．

解答 解：將100g 98%的濃硫酸溶于400g水中，所得溶液中溶質(zhì)的質(zhì)量分?jǐn)?shù)為$\frac{100g×98%}{100g+400g}$×100%=19.6%．
答：稀硫酸中H₂SO₄的質(zhì)量分?jǐn)?shù)為19.6%．

點(diǎn)評 本題難度不大，掌握溶質(zhì)質(zhì)量=溶液質(zhì)量×溶質(zhì)的質(zhì)量分?jǐn)?shù)、溶質(zhì)質(zhì)量分?jǐn)?shù)=$\frac{溶質(zhì)質(zhì)量}{溶液質(zhì)量}$×100%是正確解答本題的關(guān)鍵．