Where:
Ms= mass of specimen (KG)
Mc= mass of colorimeter (KG)
Mw= mass of water in calorimeter (KG)
T initial specimen = initial temperature of the specimen (°C)
T final specimen = final temperature of the specimen (°C)
T initial water = Initial temperature of the water (°C)
T final water = final temperature water (°C)
This equation then becomes:
Ms Cps ΔTs= mw Cpw Δtw
Where ΔTs = (T initial specimen – T final specimen and ΔTw = (T final water- T initial water)
Our aim in this experiment was to measure the specific heat capacity of a metal sample using a calorimeter, and establish what metal samples we had, i.e. copper, iron etc.
Method
- Determine the mass in Kg of each metal sample
- Using its attached cord, carefully place one of the metal samples into the beaker of water and heat to boiling point. The sample should soak in the water until it is at the same temperature as the water. Measure the temperature of the boiling water
- Weigh the empty calorimeter (including its lid and stirrer)
- Remove the calorimeter from the balance and add room temperature water until it is about half full.
- Calculate the mass of the water added.
- Measure the temperature of the water in the calorimeter
- Remove the lid and stirrer from the calorimeter, using the attached chord, and quickly but carefully take the sample from the boiling water and place it in the calorimeter. Do not drop it, as the calorimeter is fragile.
- Quickly replace the lid, stirrer and thermometer and observe the rise in temperature of the water, stirring continually. The change in temperature is small and happens quickly
- Note the temperature of the water when it has reached a steady maximum,
- Calculate the specific heat capacity.
- Empty the contents of the calorimeter and repeat the experiment for the other metal samples.
The specific heat capacity of water Cpw = 4.187Kj/Kg K
Metal specimen 1
Calorimeter weight = 409g (0.409kg)
Calorimeter weight with water = 490.3g (0.490kg)
Mass of water = 0.81g (0.081kg)
Temperature of colorimeter (cold water) = 22.4°C
Temperature of boiling water= 99.8°C
Calorimeter temperature with metal specimen in = 28.8°C
MsCps (TInitial specimen – T final specimen) = mwCpw (Tfinal water – Tinitial water)
Cps = mwCpw (Tfinal water – Tinitial water)
Ms(TInitial specimen – T final specimen)
Cps = 0.081kg × 4.187 × (28.8 – 22.4)
0.084kg × (99.8 – 28.8)
Cps = 0.364
The specific heat capacity of Copper = 0.385
Metal specimen 2
Calorimeter weight = 409g (0.409kg)
Calorimeter weight with water = 485.3g (0.485kg)
Mass of water = 0.76g (0.076kg)
Temperature of colorimeter (cold water) = 22.1°C
Temperature of boiling water= 99.5°C
Calorimeter temperature with metal specimen in = 27.5°C
MsCps (TInitial specimen – T final specimen) = mwCpw (Tfinal water – Tinitial water)
Cps = mwCpw (Tfinal water – Tinitial water)
Ms(TInitial specimen – T final specimen)
Cps = 0.076kg× 4.187 × (27.5 – 22.1)
0.03kg× (99.5 -27.5)
Cps = 0.796
The specific heat capacity of Aluminium = 0.897
Metal specimen 3
Calorimeter weight = 409g (0.409kg)
Calorimeter weight with water = 484.4g (0.484kg)
Mass of water = 0.75g (0.075kg)
Temperature of colorimeter (cold water) = 21.7°C
Temperature of boiling water= 99.1°C
Calorimeter temperature with metal specimen in = 24.8°C
MsCps (TInitial specimen – T final specimen) = mwCpw (Tfinal water – Tinitial water)
Cps = mwCpw (Tfinal water – Tinitial water)
Ms(TInitial specimen – T final specimen)
Cps = 0.075kg × 4.187 × (24.8 – 21.7)
0.105kg × (99.1 – 22.8)
Cps = 0.124
The specific heat capacity of Lead = 0.127
Conclusion
I identified the metals used in this experiment to be:
- Specimen 1 = Copper
- Specimen 2 = Aluminium
- Specimen 3 = Lead
The specific heat for the metal specimen I got from this experiment were slightly inaccurate, to what the specific heat of the metal specimens should have been, there are many reasons why this may of occurred, the most obvious one of them is when I removed the metal specimen from the boiling water and placed it into the calorimeter, the specimen in my opinion is going to loose a bit of its heat in the transfer. Another reason may have been when I placed the lid on the calorimeter it may not have been placed properly causing a loss of heat. The calorimeter will lose some energy from the specimen through convection through the water to the inside wall of the calorimeter and then conduction through the calorimeter’s wall. Also while stirring it was essential that the water was stirred continually through to when I got the temperature reading, this also could have been one of the reasons why my results were slightly inaccurate, as I may not have stirred it well enough. All in all the results I obtained were only slightly inaccurate, how ever once I got the results and compared them to the chart it was clear what the metal specimen were.
