Answer to Question #257734 in Physical Chemistry for Deepika

Question

Justify the following statements according to your perception: -

I. For enthalpy of bond formation, the term average energy is usually used

II. For enthalpy of solution, the term integral enthalpy is usually used

III. Lattice energy is always negative

IV. In the case of an exothermic reaction, the product have a high boiling point

Answer 1

I. All the similar bonds in a molecule do not have the same bond enthalpies. E.g. In undergoes some change becuase of charged chemical envrionment. Therefore, in polyatomic molecules the term mean or average bond enthalpy is used.

II. Integral Enthalpy Of Solution is the heat absorbed or released when a solute is dissolved in a definite amount of solvent. The heat of solution depends on the nature of the solute and on its concentration in the final solution.

III. potential energy that may be defined in two ways. As implied in the definition, this process will always be exothermic, and thus the value for lattice energy will be negative. Its values are usually expressed with the units kJ/mol.