P1.2 Changes Of State

Question 1

Source of inaccuracy for SHC: Thermal energy passing out the beaker and into the air

Answer 1

Use an insulator with a lower thermal conductivity

Question 2

Source of inaccuracy for SHC: not all energy from immersion heater passing into the oil

Answer 2

Ensure immersion heater is fully submerged

Question 3

Source of inaccuracy SHC: incorrectly reading the thermometer

Answer 3

Use an electric temperature probe

Question 4

Source of inaccuracy SHC: thermal energy may not be spread through the oil

Answer 4

Stir the oil

Question 5

Describe SHC practical

Answer 5

1) set weighing scale to 0
2) add oil to the beaker and record the mass
3) place an immersion heater and thermometer into the beaker
4) wrap the beaker in insulating foam to reduce energy transfer to surroundings
5) read the starting temperature of the oil
6) connect immersion heater to Joule-meter and power pack
7) turn on immersion heater and wait for 30 minutes
8) when the time is up check the number of Joules transferred through the immersion heater, record temperature
9) insert values into the formula (c= change in energy/change in temp x mass)