If a 4.0-L container of helium gas has a pressure of 10.0 atm, what pressure does the gas exert if the volume is increased to 6.0 L?
If a 4.0-L container of helium gas has a pressure of 10.0 atm, what pressure does the gas exert if the volume is increased to 6.0 L?
Step [1] Identify the known quantities and the desired quantity.
• To solve an equation using Boyle’s law, we must know three quantities and solve for one quantity. In this case P_{1}, V_{1}, and V_{2}are known and the final pressure, P_{2}, must be determined.
P_{1} = 10.0 atm
V_{1}= 4.0 L V_{2} = 6.0 L P
known quantities
P_{2} = ?
desired quantity
Step [2] Write the equation and rearrange it to isolate the desired quantity on one side.
• Rearrange the equation for Boyle’s law so that the unknown quantity,P_{2} , is present alone on one side.
Step [3] Solve the problem.
• Substitute the known quantities into the equation and solve for P_{2}. Identical units must be used for two similar quantities (liters in this case) so that the units cancel.
• In this example, the volume increased so the pressure decreased.