Answer :
Final answer:
The total energy required to melt and vaporize sodium is the sum of the enthalpy of fusion and enthalpy of vaporization, which equals 100.8 kJ/mol. The correct answer is (c) 100.8 kJ/mol. The correct answer is C.
Explanation:
The enthalpy of fusion for sodium metal is 2.6 kJ/mol and the enthalpy of vaporization is 98.2 kJ/mol. The total energy required to melt and then vaporize sodium would be the sum of both the enthalpy of fusion and enthalpy of vaporization. Therefore, the total enthalpy change for these processes is 2.6 kJ/mol + 98.2 kJ/mol = 100.8 kJ/mol.
Answering the question posed, regarding the sum of the enthalpy of fusion and enthalpy of vaporization, the correct answer is (c) 100.8 kJ/mol.
In the context of the molar heat capacity, sodium has a relatively high value of 28.2 J/mol x 0C due to which it is used as a cooling agent in heat exchange units. Potential assumptions made with enthalpy and entropy values include the values not significantly changing with temperature variations, especially in regard to NaCl at 298 K.
