Unit 1 - Matter and Energy - Gas Laws - Regents

Question 1

What is the Kinetic Molecular Theory? (3)

Answer 1

1. Describes the behaviour of gases
2. In terms of motion
3. And relationships between gas particles

Question 2

What does the Kinetic Molecular Theory explain?

Answer 2

Describes relationship of:

1. Pressure
2. Volume
3. Temperature
4. Velocity
5. Frequency
6. Force

between collisions of gas molecules

Question 3

According to the Kinetic Molecular Theory, what is the volume of gases? (3)

Answer 3

1. Gas particles have a negligible volume
2. Most of the volume is empty space
3. Gas can be compressed very easily because you are just removing a part of the empty space!

Question 4

According to the Kinetic Molecular Theory, what is the relationship between gas particles? (4)

Answer 4

1. Have neither attractive/repelling forces
2. They don’t stick to each other OR push each other away
3. Allows them to space out & fill up the whole volume
4. If there were significant attractive forces, the gas particles would clump together, and the gas wouldn’t behave as freely compared to liquids and solids

Question 5

According to the Kinetic Molecular Theory, how do you describe the collisions? (3)

Answer 5

1. Collisions are Elastic
2. No kinetic energy in the closed system is lost
3. This helps predict gas behaviour

Question 6

According to the Kinetic Molecular Theory, how do you describe transfer of energy? (4)

Answer 6

1. When two gas particles collide, one slows down while they other speeds up!
2. This means that kinetic energy was transferred between the particles
3. However, in a closed system, although energy is getting transferred, the total kinetic energy in that system will always stay the same
4. This explains why gases maintain a consistent temperature and pressure under stable conditions

Question 7

Definition of Vacuum (4)

Answer 7

1. Empty space
2. No particles
3. No collisions
4. No Pressure

Question 8

Definition of the Ideal Gas Model (4)

Answer 8

1. Model that explains the behaviour of gases based on the KMT
2. Low Pressure and High Pressure help represent the Ideal Gas Model
3. L Pressure: Indicates less collisions
4. H Temp: High KE can overcome attractive forces

HELPFUL: WHERE WOULD A GAS LIKE TO SPEND ITS VACAY? (BEACH HAS HIGHER TEMPERATURE AND LOWER PRESSURE)

Question 9

What are two things you can do when molecules collide?

Answer 9

1. Bounce apart
2. React to form something new

Question 10

Definition of Collision Therory

Answer 10

1. In collisions, wiith proper energy and orientation
2. Chemical reactions will occur

Question 11

Definition of Pressure

Answer 11

A force exerted on a specific area

Question 12

What is the kinetic - molecular view of gas pressure?

Answer 12

More Collisions = More Pressure

The greater amount of collisions means that there is a greater force. Therefore, since pressure is force/area, pressure increases

Question 13

Standard Unit of Pressure

Answer 13

Pascal (Pa)

Question 14

Atmospheric Pressure at sea level in KiloPascal

Answer 14

101.3 kiloPascal

Question 15

Atmospheric Pressure at sea level in Atmospheres

Answer 15

1 Atmosphere

Question 16

Atmospheric Pressure at sea level in millimeters of mercury

Answer 16

760 mm Hg

Question 17

Atmospheric Pressure at sea level in Torr

Answer 17

760 Torr

Question 18

What is the relationship between temperature and velocity?

Answer 18

The greater the average kinetic energy of the molecules, the greater the speed of those molecules

Question 19

What is the relationship between mass (weight of particles) and the velocity?

Answer 19

The greater the mass, the lower the velocity

Analogy: Heavier molecules move more slowly because they need more energy to reach the same speed as lighter molecules.

Question 20

Avogrado’s Hypothesis (4)

Answer 20

1. Equal volumes of gases
2. Same temperature
3. Same Pressure
4. Equal number of particles

Mnuemonic: S.T.E.V.E.N

Same Temperature, Equal Volume, Equal Number

Question 21

Definition of Boyle’s Law (5)

Answer 21

1. As long a temp. stays the same
2. As Volume Decreases
3. Pressure Increases
4. When one goes up the other goes down
5. Smaller volume means more collisions AND MOLECULES ARE EXERTING MORE FORCE AGAINST WALLS

Analogy: If you squeeze a balloon (decrease vol.), the air inside pushes harder against the balloon (increase pressure)

Let the balloon expand (increase the volume) and the pressure inside the balloon decreases.

Question 22

Definition of Charles’ Law (4)

Answer 22

1. If pressure stays the same
2. When Temperature Increases
3. Volume Increases
4. Vice Versa - when one goes up, other goes down

Analogy:
Balloon is heated - expands
Balloon is cooled - contracts

Question 23

How does pressure influence Charles’ law?

Answer 23

The container must get bigger when heated in order for the pressure to stay the same.

Question 24

Why does an increase in temperature mean an increase in pressure (4)?

Answer 24

1. Higher Temp = Higher KE
2. Higher KE = Faster particles
3. Faster particles = more collisions with container walls
4. More collisions = Higher pressure

Question 25

WHY will pressure stay the same when the volume increases in Charles' law? (4)

Answer 25

1. When the volume increases 2. More room for faster moving particles 3. Limits # of collisions 4. Keeps pressure the same

Question 26

When should you check the pressure - before or after?

Answer 26

After

Question 27

What is the formula for Charles' law?

Answer 27

Initial Volume/Initial Temperature = Final Volume / Final Temperature

Question 28

Definition of the Combined Gas Law (3)

Answer 28

1. press. X vol /temp. of a system remains constant (RATIO) 2. Combines Boyle’s Law and Charles’s Law 3. If you change one factor, the others adjust PROPORTIONALLY to maintain equilibrium

Question 29

What occurs if there is a fixed volume for gases? (4)

Answer 29

1. Typically, if walls are flexible and gases are heated, it'll expand and push those walls back 2. However, if walls are rigid and gases are heated, the gas cannot expand 3. So, the pressure will keep building up in that container 4. If the pressure gets too high, the container will explode

Question 30

Definition of Standard Pressure & Temperature (STP) (2)

Answer 30

1. Standard conditions for temp. and pressure 2. Used as a comparison

Question 31

Formula for Boyle's Law

Answer 31

P1V1 = P2V2

Question 32

Formula for Charles' Law

Answer 32

V1 / T1 = V2 / T2