Calculate the first ionization energy of fluorine ____ KJ mol | TestHub

Passage / Comprehension

There are two attractive features about relating chemical reactivity trends to ionization energies.

i) they can be measured with fair accuracy.

ii) They can be calculated from effective nuclear charge Z* such as developed from

Slater’s rule states that the basic equation for the energy of the $n$ th electron in an atom or ion is derived from:

The $R_{H}$ value in this equation is $1312.0 k J / m o l$ . Technically, to obtain ionization energy, it is necessary to apply the above equation to each electron in the atom being ionized and then to each electron in the ion produced, and subsequently take the difference.

In practice, $Z^{*}$ values are the same in the atom and the ion for electrons deep enough in the core, which simplifies the calculation somewhat.

Calculate the first ionization energy of fluorine $____$ KJ mol

Answer:

1464

Solution:

Electron configuration of $F = 1 s^{2} 2 s^{2} 2 p^{5}$

Electron configuration of $F^{-} = 1 s^{2} 2 s^{2} 2 p^{4}$ . Ionization do not effect the nuclear charge of core 1s electron.

So ionization energy depends only on the change in valance electrons.

The effective nuclear charge for $F$ atom is 5.2 and for that of $F^{+}$ is 5.55 .

Applying the equation given $- 1312 [6 (\frac{5.55}{2})^{2} - 7 (\frac{5.2}{2})^{2}] = 1464 kJ$ .

Chemistry - PERIODIC TABLE Question with Solution | TestHub

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