M.In two moles of acetaldehyde (CH3 CHO) calculate the following a. Number of moles of carbon b. Number of moles of hydrogen

Answer: (a) 4 mol C, (b) 8 mol H, (c) 2 mol O, (d) \(1.2044 \times 10^{24}\) molecules

Molecular formula of acetaldehyde: CH₃CHO = C₂H₄O. One molecule (and so one mole) contains 2 C, 4 H and 1 O.

a) Number of moles of carbon

1 mol CH₃CHO contains 2 mol C atoms, so 2 mol contain \(2 \times 2 = 4\) mol of carbon.

b) Number of moles of hydrogen

1 mol CH₃CHO contains 4 mol H atoms, so 2 mol contain \(2 \times 4 = 8\) mol of hydrogen.

c) Number of moles of oxygen

1 mol CH₃CHO contains 1 mol O atoms, so 2 mol contain \(2 \times 1 = 2\) mol of oxygen.

d) Number of molecules of acetaldehyde

1 mol contains \(6.022 \times 10^{23}\) molecules, so 2 mol contain \(2 \times 6.022 \times 10^{23} = 1.2044 \times 10^{24}\) molecules of acetaldehyde.