Question

How can I calculate the specific heat of aluminium?

Answer 1

Hint: In order to find the specific heat of Aluminium, we must know a specific heat capacity is. Specific heat capacity is the amount of heat which is added to a substance of unit mass, in order to raise the temperature by one degree Celsius.

Complete step by step answer:
- Let us first understand about the heat capacity. It is the amount of heat which is required to raise the temperature of the substance by one degree Celsius. Now let us see what a specific capacity is. Specific heat capacity is the amount of heat which is added to a substance of unit mass, in order to raise the temperature by one degree Celsius. The quantity of specific heat is usually measured in Joules. We know that specific heat of water is around 4.184 \[J/{g^\circ }C\].
- Let us conduct an experiment so that we can calculate the specific heat of aluminium. This can be done by creating a thermal equilibrium system in which two different initial temperatures will reach the same final temperature. We have to heat the aluminium (10g) in a beaker containing water for about 10 minutes. The initial temperature of the metal is around \[{100^\circ }C\]. Now transfer the metal to a beaker containing 100 grams of water at a temperature around \[{20^\circ }C\] . The final temperature is found to be around \[{21.6^\circ }C\].
- Let us now calculate the specific heat of aluminium using the formula given below:
\[Q = mc({T_f} - {T_i})\]……. (1)
Where Q is the energy in Joules
m is the mass in Grams
c is the specific heat capacity
\[{T_f}\] is the final temperature.
\[{T_i}\] is the initial temperature.
Q is negative for the metal. This is because metal will lose heat.
Q is positive for water. This is because water will gain heat.
As the system will attain a thermal equilibrium. Specific heat of both metal and water will become equal.
\[ - {Q_{metal}} = {Q_{water}}\]
\[10g \times x \times {(21.6 - 100)^\circ }C = 100g \times 4.184J/{g^\circ }C \times {(21.6 - 20)^\circ }C\]
\[x = 0.90J/{g^\circ }C\]
The specific heat of Aluminium was found to be \[0.90J/{g^\circ }C\]

Note: Let us see some of the applications
- Cooling vessels are made of metals which have low specific capacity.
- Land and sea breezes make use of the principle of specific heat capacity.
- It is also used in the car radiators