Question

Calculate the number of kJ of heat necessary to raise the temperature of 60 g of aluminium from 35 °C to 55 °C. Molar heat capacity of Al is 24 J mol^-1 K^-1.

Answer 1

Moles of Al (n) = \(\frac{60g}{27g\ mol^{-1}}\) = 2.22 mol 

Molar heat capacity (C_m) = 24 J mol K 

∆T = 55 °C – 35 C° = 20C° or 20 K 

Now, q = C_m × n × ∆T 

= 24.0 J mol K × 2.22 mol × 20 K 

= 1065.6 J 

= 1.067 kJ