Chemistry : Unit 9 - Density of Gasses

Know what Kinetic Molecular Theory for Gasses is

explains the behavior of gasses depending on multiple variables including temperature, pressure, volume, and moles of gas.

NOTE: KMT on its own has other ideologies for solids/liquids

Know what it means to be considered an Ideal Gas

When it fits all the 5 postulates

Know the 5 Postulates that explain the behavior of an Ideal Gas

1. particles of a gas are traveling in straight lines and in constant motion. they will eventually collide w/ one another & the container

2. gasses are usually just empty space under most conditions. They are so small, that the space they occupy causes the volume to be relatively 0 (space between part = larger, part. themselves = smaller)

3. The pressure exerted on the sides of the container we. part. make contact. Although the mass of part are small, the sum is significant

4. particles of gas don’t interact w/ each other because they’re so small and the presence of intermolecular forces are non-existant. Collisions of particles are elastic.

5. Avg KE of part. of the gas is proportional to the temp. of gas in Kelvin

Know what Pressure is and how to calculate it

Pressure = amt of force per a unit (pressure exerted)

Know what Elasticity is and what it means for gas particles to experience elastic collisions

ability where smth return to its natural state after being pulled, stretched, or contacted. there is no kinetic energy lost when gas part. collide

Know what Kelvin is

temp scale related to part. motion

Know what Absolute Zero means

no particle movement, no KE

Know the specific things that will affect the behavior of a gas (i.e. Pressure, Volume, Temperature, and Moles of Gas)

pressure, temperature, volume, moles

Know what Boyle’s Law is and how to use it

states when the temp of a given mass of a confined gas is constant, the product of the pressure and vol = constant. Meaning the pressure and volume are inversely proportional.

Know what Charles’ Law is and how to use it

states which temp of a given mass of confined gasses will have a tendency to expand, resulting in a larger volume. Meaning temp and volume = directly proportional

Know what Gay Lussac’s Law is and how to use it

states when temp of a given mass pf a confined gas is increased and all other variables remain constant, gasses will have more collisions (high pressure). Meaning that pressure and temp = directly proportional

Know what Avogadro’s Law is and how to use it

states the # of moles of gas are changed within a container, the volume will also have to change. This means the vol and mols = directly proportional

Know what STP means as well as the specific conditions that are present at STP

Standard Temp and Pressure

• 1 atm = p

• t = 273 k

• r = 0.082

Know that 1 mole of any gas at STP Conditions occupies a volume of..

22.4L

Know what the Combined Gas Law is and how to use it

Know what the Ideal Gas Law is and how to use it

REMEMBER : always want volume in Liters

Know the different units of volume and what they mean

Know the different units of temperature and what they mean

Know how to derive the Density of Gasses by using the Ideal Gas Law

Molar mass = Mm

Know how to convert between different units of density by using Dimensional Analysis and Conversion Factors

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Know how to do Stoichiometry involving gasses with specific conditions

1. find limiting

2. turn into moles and convert using molar ration into ending elemnt/unit wanted

3. use this value as “n”

Know the different units of pressure and what they mean

atm - Air pressure at sea level (0ft elevation)

kPa - 1000 times the Pressure of 1 Newton per Square Meter\

torr - non-SI Unit of Pressure on the absolute scale

mmHg - Millimeters of Mercury; amount of pressure that supports 1 millimeter of mercury in a barometer

psi - Pounds per square inch

bar - Used in Meteorology; approximately equal to 1atm

Know the different units of volume and what they mean

Milliliter - The amount of space that 1 gram of water occupies under STP conditions.

Liter - The amount of space that 1 kilogram of water occupies under STP conditions.

Cubic Centimeter - The volume of a cube that has a 1cm long edge on all sides.

Cubic Meter - The volume of a cube that has a 1m long edge on all sides.

Know the different units of temp and what they mean

Fahrenheit - Temp scale based on the the Freezing Point of Brine (equal parts of Salt and Water) (0℉) and Body Temperature at Extreme Levels (100℉)

Celsius - Temp scale based on the Melting P/Freezing P of Water (0℃) and Boiling Point of Water (100℃)

Kelvin - Temp scale based on Particle Motion; 0K = No Particle Movement.