# 16.1.2 Ideal Gas Equation

### Ideal Gas Equation

• The equation of state for an ideal gas (or the ideal gas equation) can be expressed as:

pV = nRT

• The ideal gas equation can also be written in the form:

pV = NkT

• An ideal gas is therefore defined as:

A gas which obeys the equation of state pV = nRT at all pressures, volumes and temperatures

Step 3:            Substitute in values

V = 8.3 × 103 cm3 = 8.3 × 103 × 10-6 = 8.3 × 10-3 m3

T = 15 oC + 273.15 = 288.15 K #### Exam Tip

Don’t worry about remembering the values of R and k, they will both be given in the equation sheet in your exam.

### The Boltzmann Constant

• The Boltzmann constant relates the properties of microscopic particles (e.g. kinetic energy of gas molecules) to their macroscopic properties (e.g. temperature)
• This is why the units are J K-1
• Its value is very small because the increase in kinetic energy of a molecule is very small for every incremental increase in temperature ### Author: Katie

Katie has always been passionate about the sciences, and completed a degree in Astrophysics at Sheffield University. She decided that she wanted to inspire other young people, so moved to Bristol to complete a PGCE in Secondary Science. She particularly loves creating fun and absorbing materials to help students achieve their exam potential.
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