TDL1 - Ideal gas law

baws

Under the limiting conditions, real gases approach ideal gas behaviour, so real gases obey Boyle's Law when:

Low pressures → particles far apart, negligible attraction

High temperatures → molecules move fast enough that attractions are insignificant

Why real gases deviate from Boyles Law:

IMF reduce pressure exerted by gas molecules as some of their energy goes into interaction with other gas particles. And also that gas particles do take up some space themselves

• This is seen mostly at ↑P ↓T (where molecules are close enough for attractions to matter)

Charles Law

For a fixed mass of gas at constant pressure, the volume of the gas is directly proportional to its absolute temperature (in kelvins).

• ↑T = gas expands

• ↓T = gas contracts

V∝T (at constant p & n)

0K = 0 vol

Avogadro's Principle

At constant temperature and pressure, equal volumes of gas contain equal number of moles

 

Mathematically:

 𝑽 ∝ n (at constant T & p)

v1 / n1 = v2 / n2