Answer: The sample that contains the greater number of molecules is water.
Explanation: To calculate the number of molecules, it is used the Avogadro's number ( [tex]6.02*10^{23}[/tex] particles/molecules). So, considering that the mass to water and carbon dioxide is 1g (it can be any other number), the relationship between moles and molar weight is:
[tex]moles =\frac{mass}{molar weight}[/tex]
To water: [tex]moles = \frac{1g}{18 g/mol}[/tex] = 0.05 moles.
Therefore,
1 mol ---- [tex]6.02*10^{23}[/tex] molecules
0.05 moles ---- x
x = [tex]0.30*10^{23}[/tex] molecules of water.
To carbon dioxide: [tex]moles = \frac{1g}{44 g/mol}[/tex] = 0.02 moles.
Therefore,
1 mol ---- [tex]6.02*10^{23}[/tex] molecules
0.02 moles ---- y
y = [tex]0.12*10^{23}[/tex] molecules of carbon dioxide.