Respuesta :
Answer : The entropy change of the toluene is 18.5 J/K
Explanation :
To calculate the number of moles, we use the equation:
[tex]\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}[/tex]
Given mass of toluene = 46 g
Molar mass of toluene = 92.14 g/mol
Putting values in above equation, we get:
[tex]\text{Moles of ethyl toluene}=\frac{46g}{92.14g/mol}=0.499mol[/tex]
To calculate the entropy change for different phase at same temperature, we use the equation:
[tex]\Delta S=n\times \frac{\Delta H_{fusion}}{T}[/tex]
where,
[tex]\Delta S[/tex] = Entropy change = ?
n = moles of toluene = 0.499 moles
[tex]\Delta H_{fusion}[/tex] = enthalpy of fusion = 6.6 kJ/mol = 6600 J/mol (Conversion factor: 1 kJ = 1000 J)
T = temperature of the system = [tex]-95.0^oC=[-95.0+273]K=178K[/tex]
Putting values in above equation, we get:
[tex]\Delta S=\frac{0.499mol\times 6600J/mol}{178K}\\\\\Delta S=18.5J/K[/tex]
Hence, the entropy change of the toluene is 18.5 J/K
