Edward Valadez

Notes
Temperature = Volume x Pressure / Constant
Volume = Constant x Temperature / Pressure
Pressure = Constant x Temperature / Volume
Pressure x Volume/Temperature = Constant
Pressure needs to be in the same unit, Volume needs to be in the same unit, Temp has to be in K
The Combined Gas Law is a combination of Boyle's and Charles' Laws. The Combined Gas Law describes
the relationship between pressure, volume, and temperature. For example, if the pressure increased,
wither the volume would decrease or the temperature would increase.
The Combined Gas Law can be used to solve any Boyle's or Charles' Law problem. If one of the variables
remains constant, disregard that variable by leaving it out of your equation or setting it to the same
value on either side of the equals sign.
Examples
1) A cylinder contain a gas of volume 30 L, at a pressure of 110 kPa and a temperature of 420 K.
Find the temperature of the gas which has a volume 40 L at a pressure of 120 kPa.
Vi = 30 L, Pi = 110 kPa, Ti = 420 K, Vf = 40 L, Pf = 120 kPa
Step 1: Substitute the values in the below final temperature equation:
Final Temperature(Tf) = PfVfTi / PiVi
= (120 x 40 x 420) / (110 x 30)
= 2016000 / 3300
Final Temperature(Tf) = 610.91 K
2) A cylinder contain a gas of volume 10 L, at a pressure of 80 kPa and a temperature of 200 K. Find
the temperature of the gas which has a volume 20 L at a temperature of 220 K.
Vi = 10 L, Pi = 80 kPa, Ti = 200 K, Vf = 20 L, Tf = 220 kPa
Step 1: Substitute the values in the below pressure equation:
Final Pressure(Pf) = PiViTf / TiVf
= (80 x 10 x 220) / (200 x 20)
= 176000 / 4000
Final Pressure(Vf) = 44 kPa