a) Number of moles of carbon
1 molecule of CH3CHO contains 2 C-atoms.
Therefore, 2 mol of CH3CHO contains 2×2 = 4 moles of Carbon.
b) Number of moles of hydrogen
1 molecule of CH3CHO contains 4 H-atoms.
Therefore, 2 mol of CH3CHO contains 2×4 = 8 moles of Hydrogen.
c) Number of moles of oxygen
1 molecule of CH3CHO contains 1 O-atom.
Therefore, 2 mol of CH3-CHO contains 2×1 = 2 moles of Carbon.
d) Number of molecules of acetaldehyde
1 mole of acetaldehyde contains 6.022×1023 molecules,
as 2 mol will contain 2×6.022×1023 = 1.2044×1024 Acetaldehyde molecules.