Which equation is used to measure ideal gases?

The correct choice is based on the ideal gas law, which is expressed as PV = nRT. In this equation:

• P represents the pressure of the gas,

• V is the volume that the gas occupies,

• n is the number of moles of gas,

• R is the universal gas constant,

• T stands for the absolute temperature of the gas measured in Kelvin.

This equation effectively describes the relationship between the pressure, volume, temperature, and amount of an ideal gas, allowing for calculations and predictions of gas behavior under various conditions. When the conditions of a gas change (in terms of pressure, volume, or temperature), the ideal gas law provides a reliable way to understand and quantify these changes.

The other options do not accurately represent the ideal gas law: for example, the first choice lacks the volume term, while the third introduces an incorrect temperature dependency that is not part of the theory. The fourth option incorrectly rearranges the variables, misrepresenting the relationship between them. Hence, the ideal gas law is encapsulated in the correct choice, providing a foundational understanding of gas behavior in chemistry.