6.1 Gas Laws
Boyle’s Law Charles’ Law Gay Lussac’s Law Combined Gas Law Ideal Gas Law Standard Temperature and Gas STP
Gas Property Standard Measure Pressure (P) 1 atm= 101.33 kPa = 14 psi 760 mmHg = 760 Torr Temperature (T) 0 degrees C = 273.15K Volume (V) 22.4 L/mol Amount (n) Number of mols Ideal Gas Constant (R) 8.31 kPa * L/mol * K Gas Law Mathematical What it Means Description
Boyle’s Law P1V1 = P2V2 At constant temperature, as the pressure on a gas increases, its’ volume decreases. Pressure and volume are inversely proportional Charles’s Law V1/T1 = V2/T2 At constant amount of gas, as volume increases, its’ temperature increases and vice versa. Volume and temperature are directly proportional. Gay-Lussac’s Law P1/T1 = P2 /T2 At constant volume and amount of gas, as the pressure increases the temperature increases and vice versa. Pressure and Temperature
Combined Gas Law P1V1/T1 n1 = P2V2/T2n2 The ratio between the pressure- volume product and the temperature of a system remains constant. Ideal Gas Law PV = nRT The state of an amount of gas is determined by its pressure, volume, and temperature Additional Gas Theory and Gas Laws
Kinetic Molecular Theory Dalton’s Law of Partial Pressures Avogadro’s Gas Law Graham’s Law of Diffusion and Effusion Kinetic Molecular Theory
Matter is composed of particles. Gases are composed of a large number of particles that behave like hard, spherical objects in a state of constant, random, linear motion.
No energy is lost when gas particles collide. These particles move in a straight line until they collide with another particle or the walls of the container.
Particles are extremely small. These particles are much smaller than the distance between particles. Most of the volume of a gas is therefore empty space.
No attractive forces exist between particles in a gas. There is no force of attraction between gas particles or between the particles and the walls of the container. Collisions between gas particles or collisions with the walls of the container are perfectly elastic.
Particles have an average kinetic energy that varies with temperature. The average kinetic energy of a collection of gas particles depends on the temperature of the gas and nothing else. Dalton’s Law of Partial Pressures
Dalton's law states the total pressure of a mixture of gases is equal to the sum of all the individual pressures of the component gases alone.
Ptotal = P1 + P2 + P3 …. Avogadro’s Gas Law
Avogadro's law states the volume of a gas is directly proportional to the number of moles of gas when pressure and temperature remain constant. Basically: Gas has volume. Add more gas, gas takes up more volume if pressure and temperature do not change.
stp = 22.4 L/mol Graham’s Law of Diffusion and Effusion
The rate of diffusion or effusion for a gas is inversely proportional to the square root of the molar mass of the gas. Definition of Diffusion
Movement of a fluid from an area of higher concentration to an area of lower concentration. Diffusion is a result of the kinetic properties of particles of matter. The particles will mix until they are evenly distributed. Definition of Effusion
Effusion is the movement of a gas through a pore or capillary into another gaseous region or into a vacuum. Example Scenario Name of Gas Law Equation
The total pressure of a gas Dalton’s Law of Partial Ptotal = P1 + P2 + P3 …. mixture in a tank is equal to Pressures the sum of the individual pressures of the gases.
As a boy blows up a balloon, Boyle’s Law or P1V1 = P2V2 its volume increase. Avogadro’s Law
A student calculates the Ideal Gas Law PV = nRT moles of a sample of gas in a balloon after she measure the balloon’s volume , the air pressure, and air temperature. A balloon pops after landing Gay-Lusac’s Law or P1/T1 = P2 /T2 on a radiator. Charles’ Law V1/T1 = V2/T2 A large sample of air is Boyle’s Law P1V1 = P2V2 compressed into a small volume using high pressure