#### Question

Calculate the number of kJ of heat necessary to raise the temperature of 60.0 g of aluminium from 35°C to 55°C. Molar heat capacity of Al is 24 J mol^{–1 }K^{–1}.

#### Solution 1

From the expression of heat (*q*),

*q* = *m*. c. Δ*T*

Where,

c = molar heat capacity

*m* = mass of the substance

Δ*T* = change in temperature

Substituting the values in the expression of *q*:

`q = (60/27 mol)(24 J mol^(-1) K^(-1))(20K)`

*q* = 1066.7 J

*q* = 1.07 kJ

#### Solution 2

No. of moles of Al (m) = (60g)/(27 g mol^{-1)} = 2.22 mol

Molar heat capacity (C) = 24 J mol^{-1} K^{-1}.

Rise in temperature (∆T) = 55 – 35 = 20°C = 20 K

Heat evolved (q) = C x m x T = (24 J mol^{-1} K^{-1}) x (2.22 mol) x (20 K)

= 1065.6 J = 1.067 kj

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Solution Calculate the Number of Kj of Heat Necessary to Raise the Temperature of 60.0 G of Aluminium from 35°C to 55°C. Molar Heat Capacity of Al is 24 J Mol–1 K–1. Concept: Thermodynamics Applications - Enthalpy, H - Extensive and Intensive Properties.