Final answer:
To find out which substance has the maximum number of molecules, one must compare the number of moles, which is higher for substances with a lower molar mass. Since hydrogen gas (H₂) has the smallest molar mass among the options, 1g of H₂ contains the maximum number of molecules.
Step-by-step explanation:
The question asks which of the following contains the maximum number of molecules: 1g CO₂, 1g N₂, 1g H₂ or 1g CH₄. To answer this, one would need to calculate the number of moles for each substance, as 1 mole always contains the same number of molecules (Avogadro's number, 6.022 × 10²³ molecules). The substance with the lowest molar mass will yield more moles and therefore more molecules when we have the same mass (1g) of each substance.
Here are the molar masses of the given compounds:
- CO₂ = 44.01 g/mol
- N₂ = 28.02 g/mol
- H₂ = 2.02 g/mol
- CH₄ = 16.04 g/mol
Since H₂ has the smallest molar mass, it will have the largest number of moles for the same mass, and hence the greatest number of molecules. Therefore, the answer is 1g H₂.