Q. 94.2( 49 Votes )
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.
We Know that,
Q = ncΔT
Where n is number of mole of substance
c is molar heat capacity of substance
ΔT is rise in temperature
c = 24 J mol-1 K-1
ΔT = 55 – 35 = 20°C = 20 K
m = 60 g
number of mole of Aluminium in m gram is given as
n = m/M
Where M is molar mass of aluminium.
∴ n = 60/27 = 2.22
Thus Q = ncΔT
= (2.22 mol)×(24 J mol–1 K–1)×(20K)
= 1065.6 J
= 1.065 kJ
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