Question: Orthoboric acid contains: A.Pyramidal \[B{O_3}^{3 - }\] units B.Linear \[B{O_3}^{3 - }\] units ...

Question

Orthoboric acid contains:
A.Pyramidal $B{O_3}^{3 - }$ units
B.Linear $B{O_3}^{3 - }$ units
C. $T -$ Shaped $B{O_3}^{3 - }$ units
D.Triangular $B{O_3}^{3 - }$ units

Answer 1

Solution

Orthoboric acid is also known as boric acid. It is a weak boron acid sometimes used as an antiseptic, insecticide or neutron absorber and a precursor to other chemical compounds. The simplest borate anion known as the orthoborate ion $B{O_3}^{3 - }$ is known.

Complete step by step solution: We can predict which $B{O_3}^{3 - }$ unit contained in orthoboric acid. The structure of orthoboric acid is,

In the structure of orthoboric acid, there are three electron pairs which are three bond pairs. It is $s{p^2}$ hybridized, the shape of orthoboric acid is triangular planar. The orthoboric acid forms hydrogen bonds with other molecules of orthoboric acid. The orthoboric acid contain Triangular $B{O_3}^{3 - }$ units

Additional information: Orhtoboric acid has many applications in daily life as well as industry. These are listed below:
Medical use: for minor cut and burn, it can be used as an antiseptic. A very dilute solution of Boric acid can be applied as an eye wash. A dilute solution of boric acid also used as a vaginal douche for the treatment of bacterial vaginosis.
Used as insecticidal: Boric acid can be used as an insecticidal to control ants, cockroaches, fleas and many other insects.
For preserving food: Boric acid is helpful in the preservation of timber against fungal and insect attack.
Used as $pH$ buffer: Boric acid is widely used as $pH$ buffer system in equilibrium with its conjugate base-borate ion (mostly in swimming pools).
For lubrication: Boric acid can be used as lubricant on ceramic or metal surfaces. It can also be used to lubricate carrom boards.

Thus, the correct option is D.

Note: The shape of any molecule can be predicted by Valence shell ${e^ - }$ pair repulsion theory, commonly called as $VSEPR$ theory. Here ${e^ - }$ pairs refer to the bond pairs and lone pair ${e^ - }$ . The geometry of the molecules mainly depends on ${e^ - }$ pairs.