Answer:
1.01 x 10^24 molecules
Explanation: This problem is solved by remembering Avogadro's number and since we have the mass of CO, we can easily calulate the number of moles.
Molecular Weight CO : 28.01 g/mol
47.2 g * 1mol / 28.01 g = 1.68 mol
Now 1 mol of CO is 6.022 x 10^23 molecules ( Avogadro's Number) then
1.68 mol CO * 6.022 x 10^23 = 1.01 x 10^24 molecules
