Modeling a Gas

The Avogadro Constant

• Avogadro's number is the number of units in one mole of any substance , equal to 6.02214076 × 10²³

• A mole is a unit of measurement, equal to 6.02214076 × 10²³. The value of the mole is equal to the number of atoms in exactly 12 grams of pure carbon-12

• Molar mass is the mass of one mole of a substance

https://www.onlinemathlearning.com/grams-moles.html

Pressure

Ideal Gases

Ideal gases are theoretical model to gases, and they are assumed to obey the followings

• The particles are point particles, each has a negligible volume
• The molecules obey the law of motion  
• The are no forces between molecules unless when they collide (molecules do not attract or repel each other)
• The duration of collision is negligible compared with the time between collisions
• The collisions with molecules and other contain walls are elastic
• Molecules have a range of speed and move randomly

An ideal gas can be approximated by an ideal gas when the density is low or when at a high temperature and low pressure. This is because molecules are distant away from each other when density is low, so molecules will exert a weaker force on each other. 

The Pressure - Volume Law (Boyle's Law)

• At constant temperature and with a fixed quantity of gas, pressure is inversely proportional to volume and pressure times volume is equal to a constant.

Charles' law

• The volume occupied by a fixed amount of gas is directly proportional to its absolute temperature, if the pressure remains constant.

The Pressure-Temperature Law

• For a given mass and constant volume of an ideal gas, the pressure exerted on the sides of its container is directly proportional to its absolute temperature.

Ideal Gas Equation

• The state of gas can be determined when we know the volume of pressure P, volume V temperature T, and the number of moles present n. The equation related all quantities is known as the equation of state, as shown below.

Gas Laws Summary

Quiz 1: Basic Concept