Shit with temperature Flashcards
Specific heat capacity
Tells us amount of energy needed to raise temp of 1kg of a material by 1°C
Unit for specific heat capacity
J/Kg°C
How to find the change in thermal energy of a material?
Mass (kg) x specific heat capacity x temperature change (°C)
What practical fits with this topic?
Measuring the specific heat capacity of a metrical eg vegetable oil
Step 1 of specific heat capacity practical
Place beaker on a balance and press 0
Step 2
Add oil to beaker + record mass of the material
Step 3
Place thermometer and immersion heater into the oil
Step 4
Measure starting temp of the oil
Step 5
Wrap beaker in insulating foam to reduce thermal energy transfer to surroundings
Step 6
Connect joule meter to immersion heater with a powerpack to see how many joules of electrons pass into the heater
Step 7
Leave set up for 30 mins
Step 8
Read final temperature of the oil and final number of joules passed into immersion heater
Step 9
Calculate specific heat capacity using equation:
Change in thermal energy / (mass x temp change)
Sources of inaccuracy for the practical
Thermal energy could pass out of beaker into air = not accurate reading of energy
Not all thermal energy passing into oil
Incorrect reading temp
Thermal energy not spreading through the oil
How to lessen inaccuracies in the practical
Use insulator such as plastic for lower thermal conductivity
Ensure heater is fully submerged
Use elec temp probe not regulate thermometer
Stir oil regularly
Internal energy
Energy stored in a system by the particles
Includes kinetic energy and potential energy
Does temp increase when it’s changing state?
NO because the energy we are putting in is using to break the forces of attraction between particles
Latent heat
Energy required to change state of 1kg of the substance BUT with NO change in temperature
Specific latent heat of fusion
Energy required to change 1kg of substance from solid to liquid with no change in temp
Specific latent heat of vaporisation
The energy required to change 1kg of a substance from liquid to vapour/gas with no change in temp
How to find specific latent heat?
Energy for a change of state
——————————————
Mass
