Which of the following gases, when measured at standard temperature and pressure (STP), would occupy the greatest volume if 1 mole of each is considered?

• A. All gases listed would occupy the same volume at STP
• B. Oxygen (O_2)
• C. Carbon dioxide (CO_2)
• D. Hydrogen (H_2)

Answer: (A)

Verified step by step guidance

1. Recall the definition of standard temperature and pressure (STP), which is 0°C (273.15 K) and 1 atm pressure.
2. Understand that at STP, one mole of any ideal gas occupies the same volume, known as the molar volume of a gas.
3. The molar volume of an ideal gas at STP is approximately 22.4 liters per mole.
4. Since oxygen (O_2), carbon dioxide (CO_2), and hydrogen (H_2) are all gases and can be approximated as ideal gases under these conditions, 1 mole of each will occupy the same volume.
5. Therefore, the volume occupied by 1 mole of each gas at STP is equal, regardless of their molecular weights or identities.