Answer:
39.449 kJ.
Explanation:
q = m * Cp * Delta T
Where,
Delta T = temperature change in K
Cp = specific heat capacity in kJ/g.K
m = mass of the substance.
Delta T =33.4°C - (-65)°C
= 31.6 °C
q = 31.6 * 4.7 * 25
= 3713 J
= 3.713 kJ.
q = n * molar heat of vapourisation
Number of moles = mass/molar mass
= 25/17
= 1.47 mol.
q = 1.47 * 23500
= 34559 J
= 34.559 kJ.
q = m * Cp * Delta T
Delta T = -12°C - (-33.4)°C
= 21.4 °C
= 25 * 2.2 * 21.4
= 1177 J
= 1.177 kJ.
Adding all the energies together:
1.177 + 34.559 + 3.713
= 39.449 kJ
