Which of the following units is commonly used to describe the pressure of a gas?

• A. mol
• B. L
• C. K
• D. atm

Answer: (D)

Verified step by step guidance

1. Understand that pressure is a measure of force exerted per unit area by gas particles colliding with the walls of their container.
2. Recall the common units used to describe pressure in chemistry, such as atmospheres (atm), pascals (Pa), torr, and mmHg.
3. Recognize that 'mol' (moles) is a unit of amount of substance, 'L' (liters) is a unit of volume, and 'K' (Kelvin) is a unit of temperature, so none of these describe pressure.
4. Identify that 'atm' (atmosphere) is a standard unit of pressure commonly used in gas law calculations and laboratory settings.
5. Conclude that among the given options, 'atm' is the correct unit to describe the pressure of a gas.