Answer:
A 3.1 L sample of hydrogen at the same temperature and pressure contains the same number of molecules.
Explanation:
As we know ;"1 mole of any gas at STP occupies exactly 22.4 L of volume". Therefore, CO₂ and H₂ gas having same number of moles (0.20 moles) will occupy exactly the same volume.
Now, converting moles into number of molecules,
# of Molecules = Moles × 6.022 × 10²³
Putting value of mole,
# of Molecules = 0.2 mol × 6.022 × 10²³ molecules.mol⁻¹
# of Molecules = 1.20 × 10²³ molecules
Hence, both gases will contain 1.20 × 10²³ molecules.
