Factors that affect gases GASES Factors that affect

Factors that affect gases GASES

Factors that affect gases � Pressure �Force exerted when particles collide with their container � Volume �Amount of space or size of the container � Temperature �Average kinetic energy or “speed” of the particles � Moles �Amount or number of particles

Relationships � All of the factors interact and are dependent on each other � When you change one factor, it changes another factor.

Pressure Relationships � What happens to the number of collisions if you increase the size of the container? �(speed and number are constant) � What happens to the number of collisions if you increase the speed of the particles? �(size and number are constant) � What happens to the number of collisions if you add more particles? �(size and speed are constant)

Volume Relationships Imagine the container is a balloon… � What happens to the size of a container if the particles speed up? �(collisions and number are constant) � What happens to the size of a container if you add more particles? �(collisions and speed are constant)

Temperature Relationships � What happens to the speed of the particles if you add more particles? �(collisions and size are constant)

Gas Laws show relationships � Boyle’s Law – Pressure and Volume �P 1 V 1 = P 2 V 2 �Inverse relationship – one goes up, other goes down � Charles’ Law – Volume and Temperature �V 1 / T 1 = V 2 / T 2 �Direct relationship – one goes up, other goes up

Gas Laws show relationships � Gay-Lussac’s Law – Pressure and Temperature �P 1 / T 1 = P 2 / T 2 �Direct relationship – one goes up, other goes up � Avagadro’s Law – Volume and moles �V 1 / n 1 = V 2 / n 2 �Direct relationship – one goes up, other goes up

Gas Laws show relationships These are in your Reference Tables. � Combined Gas Law – Pressure, Volume, and Temperature �P 1 V 1 = P 2 V 2 T 1 T 2 � Ideal Gas Law �P 1 V 1 = P 2 V 2 T 1 n 1 T 2 n 2 or PV = n. RT R is the Universal Gas Constant

Mixtures of Gases � Dalton’s Law of Partial Pressures �Total pressure is equal to the sum of the parts �PT = P 1 + P 2 + P 3 + … � Most often used when gases are collected over water… �Gas’s pressure + Vapor Pressure of Water = Pressure reading

Rate of Effusion � Effusion is the escape of a fluid through a small opening � Graham’s Law of Effusion states that the rate of effusion is inversely proportional to the square root of the molar mass. R 1 / R 2 = √(MM 2) / √(MM 1)