For homes or businesses in some rural areas, natural gas pipelines may not be available. In such cases, methane might be obtained in a compressed gas cylinder. A common laboratory cylinder of methane has a volume of 49.0 L and is filled to a pressure of 154 atm. Suppose that all of the CH₄ from this cylinder is released and expands until its pressure falls to 1.00 atm. What volume would the CH₄ occupy?

Strategy The problem involves a change in the conditions, here pressure and volume, of a sample of gas. We will want to use the ideal gas law because it is our model that relates the various properties of a gas to one another. So we begin by assuming that the gas will obey the ideal gas law under both the initial and final conditions. We will further assume that temperature is constant because we are not given any data to suggest otherwise. Because we are working with the same sample of gas throughout, we also know that the number of moles (n) is constant. Collect the constant terms together and work toward a solution.