Question

Find the increase in energy per atom of aluminium when temperature of a piece of aluminium increases by 1ºC. (Given that 27 g of aluminium contain 6 × 10²³ atoms and the specific heat of aluminium is 0.2 cal. g^-1 ºC ^-1.)

Answer 1

Heat absorbed by 27 g of aluminium in raising its temperature by 1ºC.

Q = mc∆T

= 27 × 0.2 × 1

= 5.4 cal

= 5.4 × 4.2

= 22.68 J.

Therefore, increase in energy per atom of Al

= \(\frac{22.68}{6\times10^{23}}\) 

= 3.78 × 10^-23 J.