P1.2 & P1.3

Question 1

What is internal energy?

Answer 1

Internal energy is the total amount of kinetic and potential energy of all the particles that make up a system.

Question 2

Does temperature change during state changes? Why?

Answer 2

No, the energy goes into the breaking the forces between particles increasing the temperature.

Question 3

formula for specific heat capacity

Answer 3

Change in thermal energy = mass x specific heat capacity x temperature change

Question 4

What is specific heat capacity?

Answer 4

the energy required to raise the temperature of one kilogram of a substance by one degree Celsius

Question 5

gas to solid

Answer 5

deposition

Question 6

solid to gas

Answer 6

sublimation

Question 7

gas to liquid

Answer 7

condensation

Question 8

liquid to gas

Answer 8

boiling

Question 9

liquid to solid

Answer 9

freezing

Question 10

What is temperature?

Answer 10

Temperature is the average amount of kinetic energy between the particles.

Question 11

What happens to the mass during a stage change?

Answer 11

Mass is conserved.

Question 12

A change in the temperature of a system depends on:

Answer 12

the mass of the material
the substance of the material
the amount of energy put into the system

Question 13

Why is it easier to heat up lead rather than a liquid?

Answer 13

Since lead is a solid and the particles are only vibrating, they vibrate faster after being heated. As the particles are closer together in a solid, they are more likely to hit each other and pass the energy around.

This means that the energy spreads through the block quickly and the temperature of the block goes up quickly.

Question 14

Specific Latent Heat

Answer 14

Amount of energy needed to change the state of 1 kilo of a substance WITHOUT a change in temperature.

Question 15

specific latent heat of vaporization

Answer 15

The amount of energy required to change a unit mass of a substance from liquid to gas

Question 16

Specific latent heat of fusion

Answer 16

the energy needed to change a unit mass from the solid to the liquid phase at constant temperature

Question 17

conservation of mass

Answer 17

a principle stating that mass cannot be created or destroyed.

Question 18

internal energy

Answer 18

the sum of the kinetic and potential energies of all particles in the system
heat = increase in internal energy
cool = reduce internal energy

Question 19

specific latent heat formula

Answer 19

Energy = mass(kg) x specific latent heat

Question 20

What happens when a hot object is touching a cold one?

Answer 20

Thermal energy is transferred between the two objects. When both are at the same temperature there is no further exchange of thermal energy.

Question 21

latent heat graph

Answer 21

In the graph there are flat spots which represent the change in state (breaking/forming intermolecular bonds)

Question 22

Higher SHC meaning

Answer 22

takes more energy to increase temperature.

Question 23

SHC =

Answer 23

Energy / Mass X Temperature

Question 24

2 ways to heat up a gas

Answer 24

• Do work to it (eg. reduce volume)
• Heat it up

Question 25

pressure in a gas?

Answer 25

caused by the random movement of particles hitting the walls of the container.

Question 26

reasons by balloon get bigger?

Answer 26

we blow into them meaning more air particles more collisions ---> more higher overall force ----> higher pressure

Question 27

increasing the temperature of a gas with a sealed container?

Answer 27

increase kinetic energy ---> increases internal energy

Question 28

smaller volume =

Answer 28

bigger pressure

Question 29

This is when: pressure (p) is measured in force (F) is measured in area (A) is measured in

Answer 29

This is when: pressure (p) is measured in pascals (Pa) force (F) is measured in newtons (N) area (A) is measured in metres squared (m2)

Question 30

When a gas is compressed:

Answer 30

- Area decreases - Force increases - Pressure increases - No collisions increases - Volume decreases

Question 31

What does Boyle's law state?

Answer 31

states that pressure is inversely proportional to volume

Question 32

Boyle's Law formula

Answer 32

P1 x V1 = P2 x V2 OR pV = k

Question 33

P = pressure measured in V = volume measured in C = constant is a number in

Answer 33

P = pressure measured in Pascals (Pa) V = volume measured in m^3 C = constant is a number in Pa m^3

Question 34

What are the results of work on a gas

Answer 34

increase in internal energy increase in temperature

Question 35

atmospheric pressure

Answer 35

Force exerted by the weight of the air above. If the density of the air is greater there will be more weight of air above a surface -> this means there will more particles in a given space so there are more collisions per second causing more pressure. collsions between air molecules do not contribute to air pressure only collisions of molecules in air with a surface.

Question 36

atmospheric pressure and altitude

Answer 36

Air pressure decreases with increasing altitude

Question 37

what is the force acting on the object underwater

Answer 37

the weight of the water above it equals the force acting on it

Question 38

what does the pressure in a liquid depend on?

Answer 38

depth and density of substanse and gravitational field strength