Ideal gas laws
There are several laws to explain the behaviour of ideal gases. The first three that we will look at apply under very strict conditions. These laws are then combined to form the general gas equation and the ideal gas equation.
Before we start looking at these laws we need to look at some common conversions for units.
The following table gives the SI units. This table also shows how to convert between common units. Do not worry if some of the units are strange to you. By the end of this section you will have had a chance to see all these units in action.
Variable | SI Units | Other units |
Pressure (p) | Pascals (\(\text{Pa}\)) | \(\begin{aligned} \text{760}\text{ mm Hg} &= \text{1}\text{ atm}\\ &= \text{101 325}\text{ Pa} \\ &= \text{101.325}\text{ kPa} \end{aligned}\) |
Volume (V) | \(\text{m$^{3}$}\) | \(\begin{aligned} \text{1}\text{ m$^{3}$} & = \text{1 000 000}\text{ cm$^{3}$}\\ & = \text{1 000}\text{ dm$^{3}$} \\ & = \text{1 000}\text{ L} \end{aligned}\) |
Moles (n) | mol | |
Universal gas constant (R) | \(\text{J·K$^{-1}$·mol$^{-1}$}\) | |
Temperature (\(\text{K}\)) | Kelvin (\(\text{K}\)) | \(\text{K} = \text{℃} + \text{273}\) |
Table: Conversion table showing SI units of measurement and common conversions.
Two very useful volume relations to remember are: \(\text{1}\text{ mL} = \text{1}\text{ cm$^{3}$}\) and \(\text{1}\text{ L} = \text{1}\text{ dm$^{3}$}\).