Berapa persen (%) C, O, N dan H yang terdapat dalam urea (CO(NH2)2), jika diketahui Ar.C = 12, Ar.O = 16, Ar.N = 28 dan Ar.H =1?
Mr (CO(NH2)2) = 2.12+2.16+2.28+4.1 = 24+32+56+4 = 116
% massa C = 24/116 X 100% = 20,69 %
% massa O = 32/116 X 100% = 27,59%
% massa N = 56/116 X 100% = 48,27%
% massa H = 4/116 X 100% = 3,45%
maaf kalau salah
semoga membantu:)