Internal Energy

Question 1

What is internal energy

Answer 1

Internal energy is energy stored in the system by the particles
Internal energy is the total kinetic energy and potential energy of all the particles that make up a system 

Question 2

When we change state what happens to internal energy

Answer 2

Increase internal energy

Question 3

Solid - liquid

Answer 3

Melting

Question 4

Liquid - gas

Answer 4

Boiling

Question 5

Gas - liquid

Answer 5

Condensation

Question 6

Liquid- solid

Answer 6

Freezing

Question 7

Solid - gas

Answer 7

Sublimation

Question 8

In a change of State Mass is always

Answer 8

Conserved

Question 9

Are changes of state physical or chemical + why

Answer 9

Physical changes. If we reverse the change the material recovers its original properties

Question 10

Evaporation particles

Answer 10

On the particles on the surface have enough energy to turn into a gas

Question 11

Pressure = 1.6 x 10 ^5 
Volume = 9cm
Calculate the volume of the gas when the pressure was 1.8 x 10 ^5
Temperature is constant
Give answer + equation

Answer 11

Gases: pressure x volume = constant

1. 6 x 105 x 9.0 (1.44 x 106)
2. 44 x 106 1.8 x 105 x V

or

V = 1.44 x 106 1.8 x 105

V = 8.0 (cm³)

Question 12

The internal energy of the air increases as the tire is inflated. (2 marks) why?

Answer 12

Work is done on air

So the temperature of the air increases/ The kinetic energy of the particles increases