Question

What is the total number of lone pair of electrons in ${\mathrm{I}}_3$ an ion?

• A. $6$
• B. $9$
• C. $12$
• D. $3$

Answer 1

The correct option is B

$9$

Explanation for the correct options:

B. $9$

• Iodine has $7$electrons in the outermost shell.
• So for Three Iodine atoms. $7\times 3=21$
• It has an atomic number $53$
• It has an electronic configuration $1{\mathrm{s}}^{2}2{\mathrm{s}}^{2}2{\mathrm{p}}^{6}3{\mathrm{s}}^{2}3{\mathrm{p}}^{6}4{\mathrm{s}}^{2}3{\mathrm{d}}^{10}4{\mathrm{p}}^{6}5{\mathrm{s}}^{2}4{\mathrm{d}}^{10}5{\mathrm{p}}^5$
• As it has one negative charge also present on it so total electrons will be $22$, and have $11$pair of electrons.
• There are two bonds between three Iodine atoms and electrons are used for making bonds $4$.
• Number of electrons remaining is $18.$
• So, lone pairs present in triiodide is. $9$
• It has ${\mathrm{sp}}^3\mathrm{d}$ hybridization.
• Its shape bent shape for minimizing the repulsion between lone pairs.

• Hence option (B) is correct.,$9$ is the total number of lone pairs of electrons in ${\mathrm{I}}_3$ an ion.