PHYSICS LAB ACTIVITY
DATE:
GROUP:
MEASURING SPECIFIC HEAT CAPACITY
OBJECTIVE: To measure the specific heat capacity of some metal pieces
MATERIALS:
MEASURING INSTRUMENTS:
MEASURING
PHYSICAL QUANTITY
INSTRUMENT
SENSITIVITY
RANGE
EXPERIMENTAL SET-UP:
THEORY:
To measure specific heat in the laboratory, a calorimeter must be used. A calorimeter is a ………………………….
………………………………….. container. It is insulated to reduce …………………………………………………….. of energy to
or from the surroundings.
We know that energy always flows from an object at a ……………………………. temperature to an object at a
………………………….. temperature. If we put 2 objects in the calorimeter, a cold one and a hot one, we know
that heat will flow from the …………………….. object to the ……………………………. one until they have reached
the same temperature.
We know also that the heat gained by the cooler substance equals the heat lost by the warmer substance
(the calorimeter being an insulated container, we can assume that there is no loss of heat to the
…………………………………………………………………………….). Thus:
heat lost by substance = heat gained by water
In this experiment you put in the calorimeter a known quantity of water and a piece of metal. We know
that the specific heat of water is 4.186 J/gK (or 4186 J/kgK). We can therefore calculate the heat gained by
the water using the formula:
Heat = ………………………………………………………………………………….
As the heat gained by the water is equal to the heat lost by the metal
Heat (gained by the water) = heat (lost by the metal)
We can find the specific heat of the metal using the formula:
Specific heat = ……………………………………………………………………………………………………………
PROCEDURE:
If the hot plate is not on, turn it on. Put the beaker with water on it.
Find the mass of the metal and record its mass in the data table.
Put it sample in the water.
After your substance has been sitting in the boiling water about 3 minutes, the initial temperature of the
substance will be the same as the temperature of the boiling water.
While one person in your team is monitoring the substance in the boiling water, another member of your
team should measure 150 g of distilled water with the measuring cylinder. Put the water in the calorimeter
and measure its temperature.
When the metal sample is ready, measure again the water’s temperature and record the value in the data
table.
Carefully and quickly, extract the sample from the boiling water and put it in the calorimeter. Place the lid
on, so the thermometer sticks out the hole in the lid.
Swirl the calorimeter so the water maintains an even temperature. Do this slowly and gently so you do not
break the thermometer.
Heat from the hot substance is moving into the water. This will continue until both the water and the
substance are at the same temperature. When the thermometer has stopped rising, record the final
temperature of the system (the water and the substance are the same temperature).
If you have enough time, remove the thermometer and the substance. Discard the water in the
calorimeter. Repeat the procedure with a second sample.
DATA COLLECTION AND ANALYSIS:
metal
mmetal (g)
Tinitial metal (°C)
mwater (g)
Tinitial water (°C)
Tfinal (°C)
1
2
3
You can calculate
Twater = Tfinal – Tinitial water
Tmetal = Tfinal – Tinitial metal
To calculate the value of the specific heat of the metal you must use the following formula:
cmetal (J/gK)
𝑐𝑚𝑒𝑡𝑎𝑙 = −
………∙ ………∙ ………
………∙ ………
Compare the obtained values with the known values, as reported in the following table:
METAL
C (J/gK)
ALUMINIUM
0.903
COPPER
0.385
IRON
0.447
LEAD
0.129
Can you identify which metal have you studied?
OBSERVATIONS:
1.
Explain how you were able to identify the unknown metal. What evidence do you have to support your
claim?
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2.
Which metal would cause the greatest increase in the temperature of the water in the calorimeter: the
one with the higher specific heat, or the one with the lower specific heat? Explain.
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3.
Relative to metals, how does the specific heat of water compare: higher, or lower?
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4.
If equal masses of two metals are heated to a temperature of 100 °C, which would cause a more
severe burn – the one with the higher specific heat or the one with the lower specific heat? Explain.
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