The combined gas law, which combines Boyle's law, Charles's law, and Gay-Lussac's law, relates the pressure, volume, and temperature of a gas sample. Here are some examples of situational problems that can be solved using the combined gas law:
Changing volume and temperature at constant pressure: A gas sample occupies a volume of 2.0 L at a temperature of 300 K. If the temperature is increased to 400 K, what will be the new volume of the gas at constant pressure?
Changing pressure and temperature at constant volume: A gas sample has a pressure of 2.0 atm at a temperature of 273 K. If the temperature is increased to 373 K, what will be the new pressure of the gas at constant volume?
Changing pressure and volume at constant temperature: A gas sample occupies a volume of 4.0 L at a pressure of 2.0 atm. If the pressure is increased to 3.0 atm, what will be the new volume of the gas at constant temperature?
Combining multiple changes: A gas sample occupies a volume of 5.0 L at a pressure of 1.0 atm and a temperature of 273 K. If the pressure is increased to 2.0 atm and the temperature is raised to 373 K, what will be the final volume of the gas?
In each of these examples, the combined gas law equation can be used to solve for the unknown variable by rearranging the equation:
(P1 × V1) / T1 = (P2 × V2) / T2
Where: P1 and P2 are the initial and final pressures. V1 and V2 are the initial and final volumes. T1 and T2 are the initial and final temperatures.
By substituting the known values and solving for the unknown variable, you can find the answer to each situational problem.