Unit 1 - Matter and Energy - Gas Laws - Regents

Question 1

What is the Kinetic Molecular Theory? (2)

Answer 1

1. Describes the behaviour of gases
2. In motion & relationships between gas particles

Question 2

What does the Kinetic Molecular Theory explain? (6)

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? (Volume and Result)

Answer 3

Volume: Negligible/insignificant, mostly empty space
Result: Gas can be compressed easily

Question 4

According to the Kinetic Molecular Theory, what is the relationship between gas particles? What would happen if the opposite occured? (4)

Answer 4

Relationship - No attractive/repelling forces (sticking/pushing)
Result - Can space out & fill up the whole volume
Opposite - w/ forces, gas would clump & can’t behave freely
(compared to liquids and solids)

Question 5

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

Answer 5

Description: Elastic, so no KE was lost
Result: Helps predict gas behaviour

Question 6

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

Answer 6

Transfer of Energy: KE transferred between particles & total KE of system stays the same
Result: Gases have constant T & P in 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 (Definition, Factors, Why, Helpful)

Answer 8

Definition: Model on behaviour of gases under KMT
Factors: Lo Pressure & Hi Temp help ideal conditions
Why: Less Collisions & Hi KE overcomes attractice forces
Helpful: Where will a gas like to spend vacay (beach)

Question 9

What are two things you can do when molecules collide?

Answer 9

Bounce apart or react to form something new

Question 10

Definition of Collision Therory (2)

Answer 10

1. In order for a chemical rxn to occur
2. Collisions must occur w/ proper E & orientation

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? (3)

Answer 12

1. More Collisions = More Pressure
2. When particles collide w/ walls, force is exerted
3. More Collisions mean More Force, Pressure = Force/Area

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 (Cause, Result, Mnuemonic)

Answer 20

Cause: Gases have equal volume
Result: Same temp, pressure & number of particles
Mnuemonic: S.T.E.V.E.N - Same Temp. Equal Vol, Equal Num

Question 21

Definition of Boyle’s Law (5)

Answer 21

1. Under Constant Temperature
2. As Volume Decreases, Pressure Increases
3. Vice Versa - One goes up, other goes down
4. Smaller Vol = More Collisions
5. More Collisions = More Molecules Exerting Force on Walls

Analogy: Balloon squeezed (↓ vol.), air pushes harder against walls (↑ pressure)

Balloon expand (↑ volume), pressure inside balloon ↓

Question 22

Definition of Charles’ Law (3)

Answer 22

1. Under Constant P
2. When T Increases, V Increases to maintain P
3. Vice Versa - One goes up, other goes down

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

Question 23

How does pressure influence Charles’ law? (2)

Answer 23

1. In order for pressure to stay constant when heated
2. Container must get bigger

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 w/ 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 Vol/Initial Temp = Final Vol/Final Temp

Question 28

Definition of the Combined Gas Law (3)

Answer 28

1. Combines Boyle’s Law and Charles’s Law 2. [(P x V) /T] ratio remains constant 3. When one factor changes, others adjust PROPORTIONALLY

Question 29

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

Answer 29

1. Especially when heated, gases expand and push against flexible walls 2. When walls are rigid, gas cannot expand 3. So, P increases in container 4. When P gets too high, 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