particle model of matter - heat

Question 1

what is an objects internal store

Answer 1

the energy stored by the particles making up a system
- the total kinetic and potential energy of all the particles

Question 2

how do you find an objects internal store

Answer 2

adding the kinetic and potential stores together

Question 3

the formula for heat (thermal) capacity is …

Answer 3

heat capacity = mass x specific heat capacity.

Question 4

what is specific latent heat

Answer 4

the amount of energy needed for 1kg of a substance to change state with no change in temperature

Question 5

What is specific latent heat of fusion?

Answer 5

The energy required to change 1 kg of substance from a solid to a liquid with no change in temperature

Question 6

what is the specific latent heat of vaporisation

Answer 6

The energy required to change 1 kg substance from a liquid to gas with no change in temperature

Question 7

latent heat equation

Answer 7

energy=mass×specific latent heat ( J/kg )

Question 8

what does an increase of temperature of a system depend on

Answer 8

depends on the mass of the substance heated, the
type of material and the energy input to the system.

Question 9

what is a physical change

Answer 9

a change where you don’t end up with a new substance

Question 10

why doesn’t the temperature of substances increase as they change state

Answer 10

because as the substance is heated up, it’s internal energy increases. As the substance melts, all the energy is used to break intermolecular bonds, so there’s no increase in the substances temperature as it changes state

Question 11

what are the forces between particles

Answer 11

intermolecular

Question 12

what forces are between particles

Answer 12

intermolecular

Question 13

what gives particles kinetic energy

Answer 13

• intermolecular bonds
• chemical bonds

Question 14

what is the specific heat capacity

Answer 14

the amount of energy required to raise the temperature of 1kg of substance by 1 degree

Question 15

describe a heating graph

Answer 15

• the temperature of the solid rises as we are increasing the internal energy of the particles
• at some point, the temperature stops rising and the line becomes horizontal and at this point, the solid is changing state and turning into a liquid (melting)
• the energy we are putting in is weakening or breaking the forces of attraction between the particles, allowing the substance to change from a solid to a liquid
• eventually all the solid would have melted into a liquid, and now the temperature will start to rise agaib
• the temperature stops increasing again and becomes horizontal, because the substance is boiling as we are breaking the forces of attraction between the particles

Question 16

during change of state, what two thinngs happen

Answer 16

• we are increasing the internal energy
• but not the temperature

Question 17

How many joules does it take to melt ice?

Answer 17

334,000