Anrange the a caffeine, CHNJO b sucTOse, Cral e ethanol, CH,OH b sucrose, CraHsO
ID: 569417 • Letter: A
Question
Anrange the a caffeine, CHNJO b sucTOse, Cral e ethanol, CH,OH b sucrose, CraHsOn Fungal laccase, a blue protein found in wood-rotting fung 0.390% Cu by mass. If a fungal laccase molecule con Tour copper atoms, what is the molar mass of fungal laccas emoglobin is the protein that transports oxygen in mamm is 0.347% Fe by mass, and each hemoglobin Hemoglobin molecule of hemoglobin. reains four iron atoms. Calculate the molar mass Empirical and Molecular Formulas 81. Express the composi as the mass percents of its elements. ton of each of the following compounds a. formaldehyde, CH2O b. glucose, CoH120s e acetic acid, HCH,O2 82. Considering your answer to Exercise 81, which type of for mula, empirical or molecular, can be obtained from elementa analysis that gives percent composition? Give the empirical formula for each of the compounds rep sented belowExplanation / Answer
Ans. #81b. CH2O
1 mol formaldehyde CH2O consists of 1 mol C, 2 mol H and 1 mol O-atoms.
So,
Mass of C per mol CH2O = Moles of C x Molar mass of C
= 1 mol x (12.011 g/ mol)
= 12.011 g
Mass of H per mol CH2O = Moles of H x Molar mass of H
= 2 mol x (1.00794 g/ mol)
= 2.01588 g
Mass of O per mol CH2O = Moles of O x Molar mass of O
= 1 mol x (15.9994 g/ mol)
= 15.9994 g
# Now, mass of 1 mol CH2O = Sum of mass of constituent atoms
= 12.011 g + 2.01588 g + 15.9994 g
= 30.02628 g
# Now,
% C (w/w) = (Mass of C in 1 mol CH2O / Mass of 1 mol CH2O) x 100
= (12.011 g / 30.02628 g) x 100
= 40.0016 %
% H (w/w) = (Mass of H in 1 mol CH2O / Mass of 1 mol CH2O) x 100
= (2.01588 g / 30.02628 g) x 100
= 6.7137 %
% O (w/w) = (Mass of O in 1 mol CH2O / Mass of 1 mol CH2O) x 100
= (15.9994 g / 30.02628 g) x 100
= 53.2847 %