P1.2 Flashcards
Define specific heat capacity
The energy needed to raise the temperature of 1 kg of a material by 1 K.
What are the units for specific heat capacity?
J/Kg K
What is the equation relating temperature, energy, mass and specific heat capacity?
Change = mass x specific x Change in
In thermal (kg) heat temperature
Energy (J) capacity (K)
(J/Kg K)
What the does the amount of energy needed to raise the temperature of an object depend on?
The type of material
The mass of the material
The temperature rise
What does specific heat capacity show about the material?
It shows how resistant a material is to a change in temperature.
What does it mean if water is resistant to change in temperature? And what can water be used for?
Water is especially resistant to change in temperature.
Makes it a good material to use in central heating system.
It also means that oceans are less likely to freeze.
How is the specific capacity of the material of a saucepan?
Saucepans are made of materials with low specific heat capacities because they need to heat quickly.
However, there are other consideration when choosing a metal to make a saucepan. Good and platinum have very low specific heat capacities but are very expensive and some metals are poisonous.
Describe an experiment used to find the specific heat cap society of a substance.
Use a mass balance to measure the mass of the substance
Set up the experiment where the electric heater from the joule meter is in the substance, the joulemeter is connect to the power supply and there is a thermometer int eh substance.
The joulemeter should be calibrated and set to zero before the heater is turned on.
Measure the temperature of the substance you’re investigating using a thermometer.
Keep an eye on the thermometer. When the temperature has increased by 10 degrees, stop the experiment and record the energy non the joulemeter and then increase the temperature.
The experiment should be repeated in order to check repeatability and calculate a mean.
You can then use the equation to calculate specific heat capacity by rearranging it.
How can you reduce energy loss in an experiment?
An insulating cup helps by reducing the amount of energy that escapes from the side and the bottom of the substance you’re investigating.
Also you can further use a lid.
What is conducting gel used for?
Add a conducting gel between the heater and the metal cylinder improve conduction and make your results more accurate.
What can you use instead of a joulemeter?
You could use a voltmeter and ammeter and time how long the heater was on for, then calculate the energy supplied.
By using charge = current x time and then
Energy transferred = charge x potential difference
