Gases and Gas Laws

Flashcards about Gases, KMT, Charles’ Law Boyle’s Law and Gay-Lussac’s Law

Gas

A state of matter with no fixed volume or shape.

Kinetic Molecular Theory

Based on certain assumptions and allows us to define an “ideal gas.”

First Assumption of Kinetic Molecular Theory

Gas particles are in constant, random motion.

Second Assumption of Kinetic Molecular Theory

Individual gas particles are considered point masses, i.e. they take up negligible volume.

Third Assumption of Kinetic Molecular Theory

Gas particles do not attract or repel one another.

Fourth Assumption of Kinetic Molecular Theory

Gas particles have “elastic collisions” (like in Billiards) with each other and walls of the container kinetic energy is conserved.

Fifth Assumption of Kinetic Molecular Theory

Average kinetic energy is related to temperature.

Pressure

Force per unit area and is a physical property of a gas.

Atmospheric pressure

The force per unit area exerted by air on all objects (kilopascals, kPa).

Standard Temperature and Pressure (STP)

0°C and 101.325 kPa

Standard Ambient Temperature and Pressure (SATP)

25 °C and 100 kPa

Boyle’s Law

As the volume of a gas is decreased, the pressure of the gas increases proportionally – provided that temperature and amount of gas remain constant.

Absolute zero

The theoretical temperature at which the entities of a material contain no kinetic energy and transmit no thermal energy equal to -273.15 °C.

Charles’ Law

The volume of a gas is directly proportional to its temperature in kelvins, provided the pressure and the amount of gas remain constant.

Gay-Lussac’s Law

The pressure of a gas is directly proportional to its temperature when the amount of gas and volume remain constant.

Combined Gas Law

Describes the relationship between volume, temperature, and pressure for any fixed amount of gas.