Upon completion of this topic, learners will be able to:

• perform calculations using the Ideal Gas Equation.

Let us summarize the gas laws we have discussed so far:

We can combine these relationships into a general gas law:

and if we call the proportionality constant R, we obtain an equality:

which we can rearrange to

PV = nRT

which is the ideal-gas equation. This equation describes the relationship among the four variables P, V, T, and n.

The term R in the ideal-gas equation is the gas constant. The value for T in the ideal-gas equation must always be the absolute temperature (in kelvins instead of degrees Celsius). The quantity of gas, n, is normally expressed in moles.

The value and units of R depend on the units of P, V, n, and T. For most calculations, we will round off the value of R to three significant figures