Question

某硝酸銨樣品（混有其他雜質(zhì)，且雜質(zhì)不含氮）氮元素質(zhì)量分?jǐn)?shù)為28%，則其中硝酸銨的質(zhì)量分?jǐn)?shù)為

 

．

Answer 1

考點(diǎn)：元素的質(zhì)量分?jǐn)?shù)計(jì)算

專(zhuān)題：化學(xué)式的計(jì)算

分析：先計(jì)算出純凈硝酸銨中氮元素的質(zhì)量分?jǐn)?shù)，再計(jì)算樣品中NH₄NO₃的質(zhì)量分?jǐn)?shù)；根據(jù)混合物中某化合物的質(zhì)量分?jǐn)?shù)=

含雜質(zhì)物質(zhì)元素的質(zhì)量分?jǐn)?shù)

物質(zhì)中某元素的質(zhì)量分?jǐn)?shù)

×100%，進(jìn)行分析解答．

解答：解：純凈硝酸銨中氮元素的質(zhì)量分?jǐn)?shù)=

14×2

14+1×4+14+16×3

×100%=35%．
硝酸銨（NH₄NO₃）樣品中NH₄NO₃的質(zhì)量分?jǐn)?shù)為

28%

35%

×100%=80%．
答：硝酸銨的質(zhì)量分?jǐn)?shù)是80%．

點(diǎn)評(píng)：本題有一定難度，掌握混合物中某化合物的質(zhì)量分?jǐn)?shù)=

含雜質(zhì)物質(zhì)元素的質(zhì)量分?jǐn)?shù)

物質(zhì)中某元素的質(zhì)量分?jǐn)?shù)

×100%是正確解答本題的關(guān)鍵．