Specific Heat Capacity Flashcards
What is internal energy?
The total energy stored by the particles making up a substance or system.
What happens to the internal energy when you heat up a substance and how?
Energy is transferred to the kinetic energy store of all the particles of the substance that is being heated up which increases the internal energy.
What is the increases in internal energy by heating up an object measured by?
Temperature in degrees
What is temperature?
A measure of the average internal energy of a substance.
What is an example of different substances needing different amounts of energy to increase their temp?
4200J of energy are needed to warm kg of water by 1 degree Celsius. Whereas only 139J of energy are needed to warm 1 Kg of mercury by 1 degree Celsius.
What is the specific heat capacity?
The amount of energy needed to raise the temp of 1 Kg of a substance by 1 degree Celsius.
. the amount of energy needed to increases the temp of 1 Kg of a substance by 1 degree Celsius is the same as ….
The amount of energy 1 Kg of the same substance releases to decrease its temp by 1 degree Celsius.
What is the word formula that involves specific heat capacity, mass, temp change and change in internal energy?
change in internal energy = mass x specific heat capacity x temp change
What is the symbol formula that involves specific heat capacity, mass, temp change and change in internal energy?
∆E = mc∆θ
What do each of the symbols stand for and what unit are they measure in?
∆E = Change in internal energy (J)
m = mass (Kg)
c = Specific heat capacity (J/Kg°C)
∆θ = change in temp (°C)
How many s.f.’s should you round your answer to?
3 s.f.
Investigate specific heat capacity of solid material
OK
What will you need?
.A block of the desired material with 2 holes in it
.a thermometer
insulation for the block
.power supply
.stopwatch
.ammeter
Step 1
Measure the mass of the block and then wrap it in an insulating layer to ensure minimal energy loss.. Also, insert the thermometer and heater into the holes.
Step 2
Measure the initial temp of the block and set the pd of the power supply to be 10V. Connect an ammeter to the heater and the power supply by using crocodile clips.
Step 3
Turn on the power supply and start a stopwatch.
Step 4
As the block heats up us the thermometer to measure its temp every minute. The current shouldn’t change.
Step 5
Once you’ve collected 15 readings , turn off the power supply
What does the current in the circuit do when you turn on the power supply?
It does work on the heater, transferring energy electrically to from the power supply to the heaters thermal energy store. This energy is then transferred to the materials thermal energy store by heating causing the materials temp to increase.
You need to use calculations to calculate the specific heat capacity.
∆E = mc∆θ
You can figure out the power from the power supply by doing P = VI (10V x the current). And then power x time from the stop watch will tell you the energy transferred. You can get the temp change from the thermometer and you measured the mass at the beginning.
Last step
You can plot a graph
temp = y axis
energy transferred = x axis
Investigate Specific heat capacity of oil
Step 1
Place a beaker on a balance and set it to 0 then, add oil to the beaker and record the mass of the oil.
