Question

Calculate the change in entropy that occurs in the system when 3.10 mole of isopropyl alcohol (C3H8O) melts at its melting point (-89.5∘C). ΔH∘fus = 5.37 kJ/mol

Answer 1

Answer:

3.10 mole of C3H8O change in entropy is 89.54 J/K

Explanation:

Given data

mole = 3.10 moles

temperature = -89.5∘C = -89 + 273 = 183.5 K

ΔH∘fus = 5.37 kJ/mol =  5.3 ×10^3 J/mol

to find out

change in entropy

solution

we know change in entropy is ΔH∘fus / melting point

put these value so we get change in entropy that is

change in entropy 5.3 ×10^3 / 183.5

change in entropy is 28.88 J/mol-K

so we say 1 mole of C3H8O change in entropy is 28.88 J/mol-K

and for the  3.10 mole of C3H8O change in entropy is 3.10 ×28.88  J/K

3.10 mole of C3H8O change in entropy is 89.54 J/K

Answer 2

Answer:

ΔS = 0.0906 kJ/K

Explanation:

The entropy of a reversible process is the amount of heat energy absorbed in the process divided by the temperature in degree Kelvin. Mathematically,

ΔS = Q/T

Where:

ΔS = change in entropy (kJ/K)

Q = is the amount of heat energy absorbed (kJ)

T = Temperature of the system (K)

Thus, the change in entropy that occurs in the system when 3.10 mole of isopropyl alcohol melts at its melting point (-89.5∘C) is calculated as shown below:

Q = 3.10 mol * 5.37 kJ/mol = 16.647 kJ

T = -89.5 + 273.15 = 183.65 K

Therefore,

ΔS = Q/T = 16.647 kJ/183.65 K = 0.0906 kJ/K