Thermal Properties

Question 0

Give the equation including specific heat capacity.

Answer 0

E=mcΔT

Question 1

Define specific heat capacity.

Answer 1

The energy required to raise the temperature of 1kg of a substance by 1°.

Question 2

Describe the equipment used to determine the specific heat capacity of a solid or a liquid.

Answer 2

For a solid, an electric heater is inserted into the solid - usually a cylinder along with a thermometer. This is a surrounded by an insulating material. For a liquid, a heating coil and a thermometer are out into the liquid, the container surrounded by an insulating material and an insulating lid placed on top.

Question 3

Describe the method of the experiment to determine the specific heat capacity of a solid or a liquid.

Answer 3

Heat the substance with the heater.
Using an ammeter, and a voltmeter across the heater, we can use the equation E=VIt to calculate the energy supplied.
We then use E=mcΔt to calculate the specific heat capacity.

Question 4

Will the experimental value for specific heat capacity be higher or lower than the actual value, and why?

Answer 4

Usually much higher, because some of the energy from the heater will be transferred to the air and the container.

Question 5

How can we make the experimental value for specific heat capacity more accurate?

Answer 5

Start below room temperature and end above it, to cancel out gains and losses.

Question 6

Define the specific latent heat of fusion and vaporisation.

Answer 6

The amount of thermal energy required to change the state of 1kg of a substance. For fusion this is gas to liquid to solid, and for vaporisation is the other way around.

Question 7

Give the equation used for specific latent heat.

Answer 7

E=ml