Question

Given below are two statements:
Statement I: The correct order of first ionization enthalpy values of Li, Na, F, and Cl is $\text{Na} < \text{Li} < \text{Cl} < \text{F}$.
Statement II: The correct order of negative electron gain enthalpy values of Li, Na, F, and Cl is $\text{Na} < \text{Li} < \text{F} < \text{Cl}$.
In the light of the above statements, choose the correct answer from the options given below:

• A. Both Statement I and Statement II are true
• B. Both Statement I and Statement II are false
• C. Statement I is false but Statement II is true
• D. Statement I is true but Statement II is false

Answer 1

Answer: (A)

Both Statement I and Statement II are true

Answer 2

(i) The first ionization enthalpy order for the given elements is correctly stated as $\text{Na} < \text{Li} < \text{Cl} < \text{F}$. This is supported by the ionization energies (in kJ/mol):
$\text{Na} \, (496) < \text{Li} \, (520) < \text{Cl} \, (1256) < \text{F} \, (1681)$
(ii)The order of negative electron gain enthalpy for these elements is also correctly stated as $\text{Na} < \text{Li} < \text{F} < \text{Cl}$.
The values (in kJ/mol) are:
$\Delta_{\text{eg}}H : \text{Na} \, (-53), \, \text{Li} \, (-60), \, \text{F} \, (-328), \, \text{Cl} \, (-349)$
Thus, both statements are true.