Final answer:
The ideal gas law, represented by the equation PV = nRT, relates pressure, volume, and temperature of a gas with the number of moles and the ideal gas constant. It is a combination of other empirical gas laws and allows for calculations involving the state of a gas under various conditions, provided the gas behaves ideally.
Step-by-step explanation:
According to the ideal gas law, the relationship between pressure (P), volume (V), and temperature (T), for a given amount of gas (n), can be expressed as PV = nRT. Here, R is the ideal gas constant, and the values of P, V, and T must be in appropriate units to match the units of R, usually atmospheres for pressure, liters for volume, and kelvins for temperature. The ideal gas law is derived from combining other empirical gas laws, such as Boyle's, Charles's, and Avogadro's laws, which are all special cases of the ideal gas law, holding two of the four variables constant.
The ideal gas law allows us to calculate one variable if the other three are known. It also helps predict how a gas will respond to changes in pressure, volume, and temperature, and can be used to determine the molar mass of a gas or calculate its density if the molar mass is known. The law assumes that the gas behaves ideally, which means that the gas particles do not interact with each other, apart from elastic collisions, and that the volume occupied by the gas molecules themselves is negligible compared to the volume of the container. However, real gases show ideal behavior only under high temperatures and low pressures.