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

the correct option is c.

isotopes refers to different forms of the same element with the same atomic number but different mass number as a result of difference in their neutron numbers. isotopes have different relative atomic mass but share the same chemical properties.