Given below are two statements:
Statement I : Group 13 trivalent halides get easily hydrolyzed by water due to their covalent nature.
Statement II : AlCl₃ upon hydrolysis in acidified aqueous solution forms octahedral [Al(H₂ O)₆]³⁺ ion.
In the light of the above statements, choose the correct answer from the options given below :

Solution

Chemistry ma’am · 4 steps

Covalent halides with only six electrons on the metal invite water in, and aluminium has room for six waters.

1. Statement I. Group 13 trihalides are mostly covalent, and the central atom has only 6 electrons with an empty orbital. Water's lone pair attacks that atom, so the halide hydrolyses easily, for example BCl₃ + 3H₂O → B(OH)₃ + 3HCl. Statement I is true.
2. Statement II. In acidified water, AlCl₃ gives [Al(H₂O)₆]³⁺. Aluminium can use its empty 3d orbitals (sp³d²), so it holds six water molecules in an octahedral arrangement. The acid stops hydrolysis from going on to Al(OH)₃. Statement II is true.
3. Why boron differs. Boron is in period 2 and has no d orbitals, so its covalency stops at 4, as in [B(OH)₄]⁻. Aluminium has no such limit, which is why it can reach 6.
4. So. Both statements are true, which is option (b).

The idea to keep. Covalent, electron-deficient halides hydrolyse readily. Boron stops at coordination 4, but aluminium can use d orbitals to reach octahedral coordination 6.

Answer from the NTA final answer key. Solution by PrepWiser.