How are the pressure and volume of a gas related?

Question

anonymous · Answer

If the gas can be considered an ideal gas (a reasonable assumption in most cases), then the ideal gas law applies$$PV=nRT$$If the temperature is constant, then the right hand side of this equation is a constant. That implies that the product of the pressure and volume is a constant.

unklerhaukus · Answer

Using the result above (for a certain amount of a some gas, at a certain temperature ),  we might set the righthand side to equal a constant, say K
 $$PV = nRT = K$$
Then $$P =K/V$$ or equivalently $$V = K/P$$

In otherwords, the pressure and volume of the gas are inversely proportional.