Created By : Vaibhavi Kumari

Reviewed By : Phani Ponnapalli

Last Updated : May 17, 2023

The Gay-Lussac Law Calculator is an easy-to-use application that uses initial and final parameters to get an unknown answer quickly. This calculator tool provides quick results and critical information on basic gas characteristics during an isochoric transition.

Choose a Calculation
Initial temperature (t1)
Final pressure (p2)
Final temperature (t2)

Gay-Lussac's Law Definition

When there is a constant amount of gas in a closed and rigid container, Gay-law Lussac's (also known as the pressure law) states the relationship between pressure and temperature. According to the law, the absolute pressure is exactly proportional to the temperature.

The gas container must be made in such a way that the volume of the gas remains constant under any condition for Gay-law Lussac's to hold true. To put it another way, Gay-law Lussac's describes how an ideal gas behaves throughout an isochoric (constant-volume) process.

Gay Lussac's Law Formula

Gay-Lussac's law formula can be stated as follows P 1 T 2 = P 2 T 1

  • Where, P 1 = initial pressure of the gas
  • P 2 = final pressure of the gas
  • T 1 = initial temperature of the gas
  • T 2 = final temperature of the gas.

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How to determine Pressure or Temperature?

To determine the unknown parameters of Gay-Law Lussac's in a fraction of a second, follow the easy instructions below.

  • Step 1: Get the temperature at the start, the pressure at the start, and the temperature at the end.
  • Step 2: Multiply the starting pressure by the final temperature.
  • Step 3: To calculate the final pressure value, divide the product by the final temperature.

How do I use the Gay Lussac’s Law Calculator?

The procedures for using the calculator based on Gay Lussac's Law to find the unknown quantity are given here.

According to the International Union of Pure and Applied Chemistry (IUPAC): Standard Temperature and Pressure (STP), p₀ = 10⁵ Pa, T = 0 °C;

  • Step 1: Fill in the input fields with the specified values, such as Pi, Ti, and Tf.
  • Step 2: Write x for the unknown quantity. Let's say Pf=x.
  • Step 3: To receive the result, click the "Calculate x" button

Gay-Lussac's Law Applications

Is it possible to see how Gay-Lussac's Law operates in our daily lives? Consider the following examples:

  • 1. Tire pressure changes with the seasons - Have you ever inflated a tire in the winter only to find it overinflated when the weather warms up? Or, conversely, did the pressure drop when it cooled down when it was filled over the summer? Tires are a closed system in this scenario, thus the higher the temperature, the higher the pressure.
  • 2. Lid on a saucepan - It may appear obvious at first, but why does the lid jump and rattle around while you're heating your food in a pot? As the temperature rises, the pressure of the gas (mostly water vapour) inside the saucepan rises as well. When the pressure is high enough to remove the lid, the extra gas is released, the pressure is levelled, and the entire process begins all over again.
  • 3. If you don't trust us, try submerging a hot can in cold water. Simply heat up an empty metal can of your preferred beverage. This is something we strongly advise you to do outside, rather than at home! You can try to plug the hole after a short time and then submerge the can in cold water. If you manage, the can will shrink as the temperature inside reduces, lessening the internal pressure.

Gay-Lussac’s Law Examples

Question 1:When a gas in a cylinder is heated to 750 K, the pressure in the cylinder is 5.5 atm. If the gas's original pressure was 2.5 atm, what was its initial temperature?



Initial pressure P 1= 2.5 atm

Final pressure P 2= 5.5 atm

Final temperature T 2= 750 K

Gay-Lussac’s Law, P 1T 2= P 2T 1

T 1= (P 1T 2)/P 2

= (2.5 * 750)/5.5

= 1875/5.5

= 340.9

Hence, the initial temperature of the gas in the cylinder = 340.9 K.

Question 2:The pressure of the gas in deodorant is 5 atm at a temperature of 450 K. What was the gas's pressure when it was heated to 1500 K?



Initial pressure P 1= 5 atm

Initial temperature T 1= 450 K

Final temperature T 2= 1500 k

final pressure P 2= (P 1T 2)/T 1

= (5 * 1500)/450 = 7500/450 = 16.67

Final Pressure = 16.67

FAQs on Gay-Lussac’s Law Calculator

1. How does Gay-Lussac's Law is calculated?

When the volume of a given mass of gas remains constant, Gay-Law Lussac's asserts that the pressure varies directly with the Kelvin temperature. P1/T1=P2/T2 is the Gay-Lussac's Law formula.

2. What are the two factors covered by Gay-Lussac's law?

According to Gay-or Lussac's Amonton's law, the absolute temperature and pressure of an ideal gas are directly related under conditions of constant mass and volume. To put it another way, heating gas in a sealed container increases its pressure, but cooling a gas decreases its pressure.

3. What is the Law of Gay Lussac?

According to Gay Lussac's law, the temperature of a gas of fixed mass and volume is directly proportional to its pressure.