InterviewSolution
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                                    Let us takeone more example. What is thepercentage of carbon, hydrogen and oxygen | 
                            
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Answer»  There are 2 C atoms, 6 H atoms and 1 O2atom in 1 molecule of ethanol.So,mass of 1 molecule = 2 X mass of C atom + 6 X mass of H atom + 1 X massof O2atom = (2 X 12) + (6 X 1) + (1 X 16) {atomic wt. of C atom is 12,H atom is 1 and O2 atom is16} = 24 + 6 +16 = 46. Now, % composition ofcarbonatom is = (2 X mass of C atom)/mass of ethanol molecule= 2 X 12 / 46=24 / 46= 0.5217 To convert it into %;- =0.5217 * 100%= 52.17 % % composition ofhydrogen= (6 X mass of H atom)/mass of ethanol mol.= 6 X 1 / 46=0.1304=13.04% % composition ofoxygen= (1 X mass of oxygen atom)/mass of ethanol mol.= 1 X 16 / 46= 16 / 46 To convert it into %;- =0.3478 * 100% =34.78% thus, % composition of ethanol is52.17% C, 13.14% H and 34.78% Oby weight  | 
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