Why must we use absolute temperature in the ideal gas law?

Because in the Ideal Gas Equations, everything (pressure and/or volume) is proportional to the absolute temperature. If you use another temperature scale, you introduce an offset term which serves no purpose except to make the maths more difficult and the relationships less obvious.

Does PV nRT only apply ideal gases?

Deviations from ideal behavior of real gases The equation of state given here (PV = nRT) applies only to an ideal gas, or as an approximation to a real gas that behaves sufficiently like an ideal gas. There are in fact many different forms of the equation of state.

Are gas laws valid at absolute zero?

It appeared that an “ideal gas” at constant pressure would reach zero volume at what is now called the absolute zero of temperature. Any real gas actually condenses to a liquid or a solid at some temperature higher than absolute zero. Therefore, the ideal gas law is only an approximation to real gas behaviour.

Can you use Celsius in ideal gas law?

When using the ideal gas law, remember that temperature must be in Kelvin, not Celsius, so we will need to convert. Use the given values to solve for the final pressure.

What can occur with a real gas but not with an ideal gas?

Real gases have non-negligible excluded volume (volume between them). Ideal gases do not. When in collision with other gas particles, energy is “lost” in real gases. Ideal gases collide elastically.

Which laws can be combined to form the ideal gas law?

The combined gas law combines the three gas laws: Boyle’s Law, Charles’ Law, and Gay-Lussac’s Law. It states that the ratio of the product of pressure and volume and the absolute temperature of a gas is equal to a constant. When Avogadro’s law is added to the combined gas law, the ideal gas law results.

When can a real gas behave as an ideal gas?

Real gases behave as ideal gases most closely at low pressure and high temperature.