Paper 2

Question 1

what is specific heat capacity?

Answer 1

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

Question 2

what does heating a substance do?

Answer 2

increase the energy in its thermal energy store, it is sometimes referred to internal energy of a substance

Question 3

what is the internal energy of a substance?

Answer 3

the actual sum of the energy in the kinetic and potential stores of the particles and you measure this by temperature

Question 4

what do materials that need to gain lots of energy to warm up do?

Answer 4

release lots of energy when they cool down

Question 5

what is the equation for specific heat capacity?

Answer 5

change in thermal energy = mass x specific heat capacity x temperature change
ΔQ = m x c x Δθ

Question 6

how can you find the specific heat capacity of water?

Answer 6

1. Use a mass balance to weigh insulating container
2. Fill with water and weigh again, difference is mass of water in container
3. attach joulemeter to power supply and attach to electric emersion heater which should sit in the water with a thermometer
4. place lid on container if you have one and make sure joulemeter reads zero
5. when temp has increased by 10 degrees stop experiment and record energy on joulemeter and temp increase
6. calculate SHC
7. repeat experiment and create an average

Question 7

in the SHC experiment what could you use instead of a joulemeter?

Answer 7

voltmeter or ammeter and time how long the heater was on for then calculate the energy supplied

Question 8

define specific latent heat?

Answer 8

the amount of energy needed to change the state of 1kg of substance

Question 9

what happens when you heat a solid or a liquid?

Answer 9

you are transferring energy to the kinetic energy stores of the particles in the substance making the particles move faster or vibrate

Question 10

what happens when a substance is melting or boiling?

Answer 10

you are putting in energy but it is being used to break intermolecular bonds rather than raising the temperature

Question 11

what happens when a substance is condensing or freezing?

Answer 11

bonds are forming between particles which releases energy meaning the temperature doesn’t go down until all the substance has turned into liquid or a solid

Question 12

specific latent heat of fusion?

Answer 12

the SLH for changing between a solid and a liquid - melting or freezing

Question 13

specific latent heat of vaporisation?

Answer 13

the changing between a liquid and a gas - boiling, condensing or evaporating

Question 14

what is the equation for specific latent heat?

Answer 14

thermal energy = mass x SLH

Q = m x L