Chemistry: KMT and Gas Laws

Kinetic Molecular Theory (KMT)

Based upon the idea that particles of matter are always in motion.

gas

Which state of matter’s particle arrangement is being describe:

Total disorder; much empty space; particles have complete freedom of motion; particles far apart.

liquid

Which state of matter’s particle arrangement is being describe:

Disorder; particles are free to move relative to each other; particles close together

crystalline solid

Which state of matter’s particle arrangement is being describe:

Ordered arrangement; particles are essentially in fixed positions; particles close together

molecules

Kinetic Molecular Theory is an important theory for explaining the behavior of _________ in matter.

moving particles

Kinetic Molecular theory shows how all matter is made up of ________ _________ too small to be seen with the smallest microscope.

gases

Kinetic Molecular Theory helps explain physical properties and behavior of which state of matter?

small particles

The Kinetic Molecular theory states all matter is composed of what?

kinetic energy

The Kinetic Molecular theory states that the particles in matter are in constant random motion; they possess what kind of energy?

gas

The Kinetic Molecular theory states that _____ particles move in a straight line, and they collide with each other or the wall of their container; the collision between particles are perfectly elastic, which means “no loss of energy.”

do not

The Kinetic Molecular theory states that gas particles _____ attract or repel each other.

temperature

The Kinetic Molecular theory states that the average kinetic energy of the particles depends on the __________ of the gas (gas particles only - this is Kelvin temperature)

kinetic energy

The energy due to the motion of a particle

velocity

Increase in kinetic energy means more particle motion, greater ________ (speed).

slowly

Do bigger particles move faster or slowly?

Temperature

A measure of the average kinetic energy of the particles in a substance.

yes

If the 2 substances have the same temperature, do they have the same KE regardless of particles present?

direct (Increase T, increase KE; Decrease T, decrease KE)

Does temperature and KE have a direct or indirect relationship?

fahrenheit, celsius, kelvin

Name the 3 units of temperature.

farenheit

Unit of temperature used in the U.S. (based on average human body temperature)

celsius

Unit of temperature used in the U.K. (based on movement of water)

Kelvin

Unit of temperature used in science (based on movement of particles)

K = C + 273

Formula for converting Celsius to Kelvin.

C = K - 273

Formula for converting Kelvin to Celsius.

standard temperature

the freezing point of pure water at sea level in air at standard pressure (1 atm)a

absolute zero

Is a theoretical temperature, it is the lowest possible temperature where nothing could be colder and no heat energy remains in the substance.

no (they are completely at rest)

During the absolute zero temperature, do atoms transmit thermal energy?

pressure

The amount of force applied over a surface area

pressure = force/area

Formula for pressure.

increase

In a rigid container, there is an increase in temperature and a _________ in pressure.

decrease

In a rigid container, there is an decrease in temperature and a _________ in pressure.

Newtons (N)

What unit is used to measure force (a push or pull)?

m², cm², mm², km²

What units are used to measure area (length x width)?

torr, kPa (kiloPascals), bar, atm (atmosphere), Pa, mmHg (millimeter of Mercury), psi (pounds per square inch)

What are the standard units of pressure?

gas molecules

Can apply pressure on the walls of a container. Ex: Shake up a coke bottle…. The bottle becomes harder because you’ve increased the pressure inside the bottle.

Barometer

A device used to measure air pressure.

Internal Pressure/Gas (vapor) Pressure

Depends on the number of collisions with the inside wall of the container

direct

Do pressure and temperature have a direct or inverse relationship?

Atmospheric Pressure (air pressure)/External Pressure

Results from the collisions of air molecules with the outside of objects.

yes (no volume = lots of empty space)

Can gases be compressed?

diffusion

Gases undergo _______ - random motion.

diffusion

Is movement of molecules from a region of high concentration to a region of low concentration.

mass; temperature

Diffusion depends on the ______ (or size) of the particles and ___________.

Lighter

________ (Lighter or Heavier?) molecules travel faster, have more frequent collisions and thus diffuse more rapidly. Higher temperatures will cause particles to diffuse rapidly as well.

properties of gases

What was one of the earliest phenomena that chemists studied?

gas laws

Laws that bring together temperature, volume, and pressure and helps us see how those factors are related.

constant

The gas laws state that the number of gas particles remains _________.

closed

Gas laws are only relevant in __________ systems.

Robert Boyle

Anglo-Irish philosopher, chemist, physicist and alchemist. He studied the relationship the volume and pressure of a sample of gas. He’s known for his book The Skeptical Chemist. He refuted Aristotle’s idea that all matter was composed of earth, air, fire, and water.

Boyle’s Law

Law that states if the temperature is constant, when the pressure goes up, the volume goes down. This is an inverse relationship.

a curve

What shape is the graph of an inverse curve?

P₁ x V₁ = P₂ x V₂

What is Boyles Law formula?

Jacques Charles

• French physicist

• He was on the second balloon ever to lift a human being off the surface of the earth

• Studied the effect of temperature on the volume of a gas at constant pressure

Charles’ Law

The law that states if the pressure is constant, when the temperature goes up, the volume goes up (elastic container). This is a direct relationship.

a straight line

What does the graph of a direct relationship look like (for Charles’ Law)?

V₁/T₁ = V₂/T₂

What is Charles’ Law formula?

Joseph-Louis Gay-Lussac

• French Chemist

• Charles never published his work, so this chemist repeated Charles’ work and published the results.

• He followed up the work changing the container to a rigid container

Gay-Lussac’s Law

Law that states if the volume is constant, when the temperature goes up, the pressure will go up (rigid container). This a direct relationship.

a straight line

What does the graph of a direct relationship look like (Gay-Lussac’s Law)?

P₁/T₁ = P₂/T₂

Gay Lussac’s formula.