JAMB - Chemistry (2003 - No. 3)
What is the percentage by mass of oxygen in Al2(SO4)3. 2H2O?
[Al = 27, S = 32, H = 1, O = 16]
[Al = 27, S = 32, H = 1, O = 16]
14.29%
25.39%
50.79%
59.25%
설명
Al2(SO4)3. 2H2O
2 * 27 + 3*32 + 14 * 16 + 4 * 1 =
54 + 96 + 224 + 4 = 378
% O2 = (224/378) * (100/1) = 59.25%
2 * 27 + 3*32 + 14 * 16 + 4 * 1 =
54 + 96 + 224 + 4 = 378
% O2 = (224/378) * (100/1) = 59.25%