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# Gay-Lussac's Law Tutorial

## Gay-Lussac's Law Tutorial

##### Gay-Lussac's Law:

Gay-Lussac's Law states that the pressure of a fixed amount of gas at fixed volume is directly proportional to its temperature in kelvins.

#### Gay-Lussac's Law Formula :

Gas Equation: Pi/Ti = Pf / Tf Initial Pressure(Pi) = PfTi / Tf Initial Temperature(Ti) = PiTf / Pf Final Pressure(Pf) = PiTf / Ti Final Temperature(Tf) = PfTi / Pi where, Pi = Initial Pressure, Ti = Initial Temperature, Pf = Final Pressure. Tf = Final Temperature
##### Gay-Lussac's Law Example

Case 1: A cylinder contain a gas which has a pressure of 125kPa at a temperature of 200 K. Find the temperature of the gas which has a pressure of 100 kPa.

Pi = 125 kPa, Ti = 200 K, Pf = 100 kPa

##### Step 1:

Substitute the values in the below final temperature equation: Final Temperature(Tf) = PfTi / Pi = (100 x 200) / 100 = 20000 / 125 Final Temperature(Tf) = 160 K This example will guide you to calculate the final temperature manually. Case 2: Find the final pressure of gas at 150 K, if the pressure of gas is 210 kPa at 120 K. Pi = 210 kPa, Ti = 120 K, Tf = 150 K

##### Step 1:

Substitute the values in the below pressure equation:

Final Pressure(Pf) = PiTf / Ti = (210 x 150) / 120 = 31500 / 120 Final Pressure(Vf) = 262.5 kPa This example will guide you to calculate the pressure manually.

This tutorial will help you dynamically to find the Gay-Lussac's Law problems.