Chemistry CH 12 Study Guide
STP
22.41 L is the volume of 1 mol of any gas at ____________________.
ideal
An ____________________ gas is an imaginary gas whose particles are infinitely small and do not interact with each other.
temperature and pressure
At constant _________________________, gas volume is directly proportional to the number of moles of gas.
temperature
Charles's law is the direct relationship between ____________________ and volume.
fluids
Gases are ____________________ because they are able to flow.
effusion
Gay-Lussac's law of combining volumes of gases
inversely
Graham's law of diffusion states that the rate of diffusion is ____________________ proportional to the square root of the gas's density.
They move from areas of high concentration to areas of low concentration.
How do substances move during diffusion?
The atmosphere exerts pressure on the surface of mercury in the barometer. This pressure forces the fluid up the column of mercury. The mercury settles at a point where the pressure exerted downward by its weight equals the pressure exerted by the atmosphere.
How does a mercury barometer work?
All the gas molecules move randomly. Each gas exerts a pressure proportional to the number of gas molecules in a container. The presence of other gas molecules does not change that situation.
How is Dalton's law of partial pressure explained by the kinetic-molecular theory?
attractive
In a real gas, all the particles exert ____________________ forces on each other.
molar mass of the gas
Knowing the mass and volume of a gas at STP allows one to calculate the _________________________.
Boyle's law
Pressure and volume changes at a constant temperature can be calculated using ____________________.
surface area
Pressure is the force per unit ____________________.
0, 1
Standard temperature and pressure is equal to _____°C and _____ atm.
pascal
The SI unit for pressure is the ____________________.
kinetic-molecular
The ____________________ theory says particles of matter are in constant motion.
pressure
The constant bombardment of gas molecules against the inside of a container produces ____________________.
gas
The law of combining volumes applies only to ____________________ volumes measured at constant temperature and pressure.
distance
The most significant difference between liquids and gases is the ____________________ between particles.
partial
The pressure of each gas in a mixture is called the ____________________ pressure.
Avogadro
The principle that under similar pressures and temperatures, equal volumes of gases contain the same number of molecules is attributed to ____________________.
diffusion
The process of ____________________ involves an increase in entropy.
Gay-Lussac's law of combining volumes of gases
The reaction of two volumes of hydrogen gas with one volume of oxygen gas to produce two volumes of water vapor is an example of _______________________________________________________.
decreases
The volume of a gas ____________________ during compression.
Earth's atmosphere is a mixture of gases. These gases are being pulled toward Earth's surface by gravity. As they are pulled, they collide with each other and the surface of Earth. These collisions cause air pressure.
What causes air pressure?
He noted that at constant temperature and pressure, the rate of effusion of a gas is inversely proportional to the square root of the gas's molar mass.
What did Thomas Graham have to say about effusion?
Avogadro's law states that equal volumes of different gases under the same conditions of temperature and pressure have the same number of molecules.
What is Avogadro's law?
Boyle's law is the inverse relationship between pressure and volume.
What is Boyle's law?
Charles's law is the direct relationship between temperature and volume.
What is Charles's law?
It is the law that states that the volumes of gases involved in a chemical change can be represented by the ratio of small whole numbers.
What is Gay-Lussac's law of combining volumes?
It is the direct relationship between temperature and pressure.
What is Gay-Lussac's law?
Scientists have named a standard temperature and pressure to compare the effects of changing temperature and pressure on a gas. This standard is equal to 0°C and 1 atm.
What is STP?
The mass of 22.41 L of a gas at 0°C and a pressure of 1 atm is the gas's molecular mass.
What is a gas's molecular mass?
An ideal gas does not condense to a liquid at low temperatures, does not have forces of attraction or repulsion between the particles, and is composed of particles that have no volume.
What is the difference between an ideal gas and a real gas?
The ideal gas law is an equation that involves four variables: pressure, volume, absolute temperature, and number of moles.
What is the ideal gas law?
Gases are fluids because they are able to flow. Gas particles can flow because their particles are relatively far apart and therefore are able to move past each other easily.
Why are gases considered to be fluids?
Changes in density as altitude increases cause your ears to "pop". The atmosphere is denser closer to the surface of Earth. As an airplane rises in altitude, there is less air pressure. The "pop" occurs when the air inside your ears changes to the same pressure as the outside air.
Why do your ears "pop" in an airplane?
At those conditions, the volume of the particles and the forces of attraction between them are negligible. Changes in volume and temperature can make the ideal gas law less useful.
Why does is the ideal gas law best able to explain the behavior of real gases at room temperature and atmospheric pressure?
Boiling point is dependent on the external pressure and the vapor pressure of the liquid. Standard pressure is 1 atm. If atmospheric pressure is less than 1 atm, the boiling point will be lower.
Why is the boiling point of a substance at low pressure lower than the boiling point at standard pressure?