P6.5 - Specific Latent Heat

Question 2

What is the latent heat of fusion?

Answer 2

The energy supplied to a solid substance at it’s melting point for it to melt and turn to a liquid

Question 3

What happens to latent heat when liquids cool and solidify?

Answer 3

It is transferred to the surroundings as the substance solidifies

Question 4

What is the specific latent heat of fusion of a substance?

Answer 4

The energy needed to change the state of 1kg of the substance from solid to liquid, at its melting point

Question 5

What is the unit of specific latent heat of fusion?

Answer 5

J/Kg, joules per kilogram

Question 6

How do you calculate specific latent heat of fusion?

Answer 6

Specific latent heat of fusion = energy transferred / mass

Question 7

How do you calculate the energy needed to change a substance from solid to liquid?

Answer 7

Energy = mass * specific latent heat of fusion

Question 8

What is latent heat of vaporisation?

Answer 8

The energy supplied to cause a liquid to turn to gas at it’s boiling point; the particles to break away from each other

Question 9

What is the specific latent heat of vaporisation?

Answer 9

The energy needed to change the state of 1kg of a substance from liquid to vapour, at it’s boiling point

Question 10

What is the equation for specific latent heat of vaporisation?

Answer 10

Specific latent heat of vaporisation = energy / mass

Question 11

What is latent heat?

Answer 11

The energy needed for a substance to change it’s state without changing its temperature