Name: Thermal Expansion of Liquid
Uploaded: 2019-07-19
Duration: 9 min 24 s
Description: Thermal expansion is the increase, or decrease, of the size of a body due to a temperature change. Thermal expansion is large for gases and small for liquids...

Question

Describe experiments to show that gases expand when heated. What are gas laws?

Accepted Answer

Experiments to show that gases expand when heated

Take an empty flask and clamp the flask in an upside-down position over a beaker of water in such a way that the glass tube dips inside the beaker.

Now heat the flask at the top.

The air in the flask expands and moves out of the flask through the tube into the beaker containing water.

Observe the bubbles of air in the water.

Now allow the beaker to cool.

As the air inside the flask contracts, the water rises up the tube.

This proves that gas like air expands on heating and contracts on cooling.

GAS LAWS:

The gas laws are a group of laws that govern the behaviour of gases by providing relationships between the following:

The volume occupied by a gas.

The pressure exerted by a gas on the walls of its container.

The absolute temperature of the gas.

The amount of gaseous substance (or) the number of moles of gas.

The gas laws were developed towards the end of the 18^th century by numerous scientists (after whom, the individual laws are named). The five gas laws are:

Boyle’s Law, which provides a relationship between the pressure and the volume of a gas.

Charles’s Law, which provides a relationship between the volume occupied by a gas and the absolute temperature.

Gay-Lussac’s Law, which provides a relationship between the pressure exerted by a gas on the walls of its container and the absolute temperature associated with the gas.

Avogadro’s Law, which provides a relationship between the volume occupied by a gas and the amount of gaseous substance.

The Combined Gas Law (or the Ideal Gas Law), which can be obtained by combining the four laws listed above.

Under standard conditions, all gasses exhibit similar behaviour. The variations in their behaviours arise when the physical parameters associated with the gas (such as temperature, pressure, and volume) are altered

Describe experiments to show that gases expand when heated. What are gas laws?

Important Questions on Thermal Expansion

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