13 th group elements (p-block) practice · Medium

Statement-I:Most of the $Al{Cl}_3$ is dimerised through halogen bridging, ${Al}_2 {Cl}_6$

Statement-II: ${AlCl}_3$ complete its octet by accepting electrons from halogen in halogen bridged molecules, ${Al}_2 {Cl}_6$

Assertion (A): $\mathrm{HBF}_4$ is a very strong acid.

Reason $(\mathbf{R}): \mathrm{B}(\mathrm{OH})_3$ behaves as an acid in the following reaction :
$\mathrm{B}(\mathrm{OH})_3+4 \mathrm{HF} \longrightarrow \mathrm{H}_3 \mathrm{O}^{+}+\left[\mathrm{BF}_4 \right]^{-}+2 \mathrm{H}_2 \mathrm{O}.$

Consider the following statements

(i) Aluminium carbide on reaction with water gives methane gas.

(ii) Permanent hardness of water is easily removed by boiling

(iii) ${H}_2 {O}_2$ dipole moment is more than that of ${H}_2 {O}$

(iv) Potassium impart blue colour to the flame test.

Incorrect statements among the following are

In alumino thermic process, Al is used as

The increasing order of atomic radii of group – 13 elements is

Boric acid on heating at $150^\circ C$ gives:

In which one of the following molecules strongest back donation of an electron pair from halide to boron is expected?

Assertion (A): Aqueous solution of borax is acidic in nature.

Reason (R): Borax on reaction with aqueous hydrochloric acid gives boric acid as one of the products.

In light of the above statements, choose the correct answer.