10. The enthalpy of fusion for benzene (C6H6, 78.0 g/mol) is 127.40 kJ/kg, and its melting point is 5.5°C. What is the entropy change when 1 mole of benzene melts at 5.5°C?

Respuesta :

Answer:

[tex]\Delta _fS=35.68\frac{J}{K}[/tex]

Explanation:

Hello,

In this case, the entropy of fusion is computed in terms of the enthalpy of fusion considering the fusion temperature in kelvins:

[tex]\Delta _fS=\frac{\Delta _fH}{T}[/tex]

Thus, since the enthalpy of fusion is given in kJ/kg we must compute the grams of benzene in mole of benzene via its molar mass:

[tex]m=1mol*\frac{78.0g}{1mol}=78g[/tex]

Next:

[tex]\Delta _fH=78g*\frac{127.4J}{g}=9937.2J[/tex]

Finally, the entropy:

[tex]\Delta _fS=\frac{9937.2J}{(5.5+273)K}\\\\\Delta _fS=35.68\frac{J}{K}[/tex]

Best regards.