How much energy must be removed from a 94.4 g sample of benzene (molar mass= 78.11 g/mol) at 322.0 K to solidify the sample and lower the temperature to 205.0 K? The following physical data may be useful. ΔHvap = 33.9 kJ/mol ΔHfus = 9.8 kJ/mol Cliq = 1.73 J/g°C Cgas = 1.06 J/g°C Csol = 1.51 J/g°C Tmelting = 279.0 K Tboiling = 353.0 K

Answer : The energy removed must be, 29.4 kJ

Explanation :

The process involved in this problem are :

The expression used will be:  

where,

= heat released for the reaction = ?

m = mass of benzene = 94.4 g

= specific heat of solid benzene =

= specific heat of liquid benzene =

= enthalpy change for fusion =

Now put all the given values in the above expression, we get:

Negative sign indicates that the heat is removed from the system.

Therefore, the energy removed must be, 29.4 kJ