Question

某不純的硝酸銨中氮的質(zhì)量分數(shù)為36%，則此硝酸銨中混入雜質(zhì)可能是（　�。�

A．NH4HCO3

B．（NH4）2SO4

C．CO（NH2）2

D．NH4Cl

Answer 1

純硝酸銨中氮元素的質(zhì)量分數(shù)=

28

80

×100%=35%；樣品中氮的質(zhì)量分數(shù)為36%＞35%，所以混入雜質(zhì)氮的質(zhì)量分數(shù)大于35%；
A、NH₄HCO₃中氮元素的質(zhì)量分數(shù)=

14

79

×100%≈17.8%
B、（NH₄）₂SO₄中氮元素的質(zhì)量分數(shù)=

28

132

×100%≈21.2%
C、CO（NH₂）₂中氮元素的質(zhì)量分數(shù)=

28

60

×100%≈46.7%
D、NH₄Cl中氮元素的質(zhì)量分數(shù)=

14

53.5

×100%≈26.2%
故選C．