Which of the following figures does not represent 1 mole of dioxygen gas at STP?

Concept:

• At STP, 1 mole of any gas occupies 22.7 L or 22.7 dm³ of volume, this is also known as molar volume.
• 1 mole of any substance contains 6.022 x 10²³ particles.
• The molar mass of the substance is the mass of 1 mole of that substance taken in grams or the amount of substance required to convert its particle mass from amu to grams.

Explanation:

• Oxygen/dioxygen gas exists in the form of O₂ molecules.
• Therefore, 1 mole of dioxygen gas contains 6.022 x 10²³ molecules of O₂.
• 1 molecule of oxygen weighs 32 amu since the mass of 1 oxygen atom is 16 amu.
• Therefore, 1 mole of dioxygen gas will weigh 32 grams.
• 1 mole of oxygen gas occupies 22.7 L of volume at standard temperature and pressure (STP).
• whereas 0.5 moles of dioxygen or 16 g of dioxygen will occupy 11.2 L of volume.

Conclusion:

Hence the correct options are options 1 and 2 as they do not represent 1 mole of dioxygen instead they indicate about a half mole of it at STP.