# Combined Gas Law Tutorial

## Combined Gas Law Tutorial

##### Combined Gas Law:

Combined Gas Law is a gas law which combines Charles's law, Boyle's law, and Gay-Lussac's law.

#### Combined Gas Law Formula :

Gas Equations: PiVi/Ti = PfVf/Tf Initial Volume(Vi) = PfVfTi / TfPi Initial Pressure(Pi) = PfVfTi / TfVi Initial Temperature(Ti) = PiViTf / PfVf Final Volume(Vf) = PiViTf / TiPf Final Pressure(Pf) = PiViTf / TiVf Final Temperature(Tf) = PfVfTi / PiVi where, Vi = Initial Volume, Pi = Initial Pressure, Ti = Initial Temperature, Vf = Final Volume, Pf = Final Pressure, Tf = Final Temperature.
##### Combined Gas Law Example:

Case 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 This example will guide you to calculate the final temperature manually. Case 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 This example will guide you to calculate the pressure manually.

This tutorial will help you dynamically to find the Combined Gas Law problems.