<u>Answer:</u> The entropy change of the ethyl acetate is 133. J/K
<u>Explanation:</u>
To calculate the number of moles, we use the equation:

Given mass of ethyl acetate = 398 g
Molar mass of ethyl acetate = 88.11 g/mol
Putting values in above equation, we get:

To calculate the entropy change for different phase at same temperature, we use the equation:

where,
= Entropy change = ?
n = moles of ethyl acetate = 4.52 moles
= enthalpy of fusion = 10.5 kJ/mol = 10500 J/mol (Conversion factor: 1 kJ = 1000 J)
T = temperature of the system = ![84.0^oC=[84+273]K=357K](https://tex.z-dn.net/?f=84.0%5EoC%3D%5B84%2B273%5DK%3D357K)
Putting values in above equation, we get:

Hence, the entropy change of the ethyl acetate is 133. J/K