Question

Calculate the change in entropy that occurs in the system when 1.24 mol of isopropyl alcohol (c3h8o) melts at its melting point (-89.5 ∘c). heat of fusion is 5.37 kj/mol.

Answer 1

Answer: The change in entropy that occurs in the system is 36.3 J/Kmol

Step-by-step explanation:

Given : 1 mole of isopropyl alcohol gives heat = 5.37 kJ

Thus 1.24 moles of isopropyl alcohol gives heat =
`(5.37)/(1)* 1.24=6.66 kJ`

To calculate the temperature , we use the equation:

`\Delta S_f=(\Delta H_(f))/(T)`

where,

`\Delta S_f` = Entropy of fusion = ?

`\Delta H_(f)` = enthalpy of fusion = 6.66 kJ/mol = 6660 J/mol (1kJ=1000J)

T = melting point =
`-89.5^0C=(273-89.5)K=183.5K`

`\Delta S_f=(6660J/mol)/(183.5K)=36.3J/Kmol`

Thus the change in entropy that occurs in the system is 36.3 J/Kmol