Identify the correct statements from the following
(a) In orthoboric acid, boron is in planar geometry
(b) In `BCI_3, NH_3`, boron has tetrahedral geometry
(c ) Aqueous solution of borax is acidic

Options

A. (i), (ii)
B. (ii), (iii)
C. (i), (iii)
D. (i), (ii), (iii)

Answer

A

Explanation

(i) In ortthoboric acid `(H_(3)BO_(3))` is boron `sp^(2)` hybridised. It forms three bonds with three hydroxyl group which lie on the same plane. Thus, in orthoboric acid, boron is in planar geometry, thus statement is correct.
(ii) `BCl_(3)` is a non-polar molecule with a symmetrical distribution of electrons and flat geometry. It forms a polar non-covalent bond with `NH_(3)` molecule due to presence of empty orbital in booron and lone pair of electrons over N-atom, which has tetrahedral geometry. Thus, statement is correct.
(iii) Borax is a salt of a strong base and a weak acid `(H_(3)BO_(3))`. Hence, it is basic in nature. Thus, this statement is incorrect.