Question

100g某硫酸溶液恰好與26g鋅完全反應(yīng)．這種硫酸溶液中溶質(zhì)的質(zhì)量分?jǐn)?shù)是多少？

Answer 1

解：設(shè)參加反應(yīng)的H₂SO₄的質(zhì)量為x
Zn+H₂SO₄=ZnSO₄+H₂↑
65 98
26g x
解得：x=39.2g
硫酸溶液中溶質(zhì)的質(zhì)量分?jǐn)?shù)是=39.2%
答：硫酸溶液中溶質(zhì)的質(zhì)量分?jǐn)?shù)是39.2%．
分析：根據(jù)鋅與硫酸反應(yīng)的方程式，由鋅的質(zhì)量可求出硫酸溶液中溶質(zhì)的質(zhì)量，再根據(jù)溶質(zhì)質(zhì)量的計(jì)算公式求出溶質(zhì)的質(zhì)量分?jǐn)?shù)．
點(diǎn)評(píng)：本題主要考查學(xué)生對(duì)物質(zhì)質(zhì)量分?jǐn)?shù)和溶質(zhì)質(zhì)量分?jǐn)?shù)的計(jì)算能力．學(xué)生需正確書寫出化學(xué)方程式，并能正確運(yùn)用溶質(zhì)質(zhì)量分?jǐn)?shù)公式進(jìn)行計(jì)算，才能正確答題．