Volume and quantity of a gas have which type of relationship?

The relationship between the volume and quantity of a gas is a direct relationship, which signifies that as the amount of gas (in moles) increases, the volume also increases, provided that temperature and pressure remain constant. This relationship is illustrated by Avogadro’s Law, which states that equal volumes of gases at the same temperature and pressure contain an equal number of molecules. Thus, if you double the amount of gas, the volume also doubles.

In contrast, an inverse relationship would imply that one quantity increases while the other decreases, which does not apply to the context of gas volume and quantity. The choices of constant and exponential do not fit as the behavior of gas volume in relation to its quantity is not characterized by a fixed value or a rapidly changing curvilinear aspect typically found in exponential relationships. Therefore, a direct relationship accurately captures the proportionality between gas volume and quantity under constant conditions.