Gas Laws Objectives

Study Notes

Gas Laws

Gas pressure changes with volume, temperature, and amount of gas molecules
To determine gas pressure changes, identify the variables that are changing (volume, temperature, or amount of gas molecules)
Standard Temperature and Pressure (STP) is 1 atm and 0°C
Temperature must be in Kelvin (K) for gas law problems, which is obtained by adding 273 to the Celsius temperature

Pressure and Amount of Gas

Pressure increases when more gas molecules are added to a container because more molecules collide with the container walls, increasing the pressure
Pressure and amount of gas are directly related
Besides increasing the amount of gas, two other ways to increase the pressure of a gas are decreasing the volume of the container and increasing the temperature

Temperature and Volume

The volume of a flexible container increases when the temperature of a gas increases as the pressure remains constant because the gas molecules gain kinetic energy and move faster, occupying more space
Temperature and volume are directly related
The volume of a gas can be calculated at different temperatures using the gas laws

Pressure and Volume

The pressure decreases when the volume of a flexible container is increased and the temperature remains constant because the gas molecules have more space to move, reducing the pressure
Pressure and volume are inversely related
The volume of a gas can be calculated at different pressures using the gas laws

Gas Stoichiometry

150.0 mL of oxygen at 0.989 atm and 22.0°C can be calculated to find its volume at STP
The number of moles of a gas can be calculated using the ideal gas law
The volume of a gas can be calculated using the ideal gas law

Phase Diagrams

A phase diagram shows the states of matter and phase changes of a substance at different temperatures and pressures
A triple point graph shows the equilibrium lines of a substance and the states of matter at different temperatures and pressures
The parts of a phase change diagram include:
- Solid phase
- Liquid phase
- Gas phase
- Melting point
- Freezing point
- Condensation
- Vaporization
- Sublimation
- Deposition
During the liquid phase, the temperature is increasing
During vaporization, the substance's temperature remains constant
Condensation involves a change from gas to liquid
The region of the graph showing liquid and gas phases existing at equilibrium is called the dew point
The phase or state of matter at segment CD is liquid
The temperature labeled T2 is the temperature at which the substance boils
The region of the graph where molecules have the highest average kinetic energy is the gas phase

Description

This quiz covers the objectives of gas laws, including determining changes in pressure and volume with varying temperature and molecular composition, and performing mathematical calculations with gas laws formulas.