Hydrogen bonding in H 3 BO 3 gives it a layered structure.

(i) It is a weak monobasic acid soluble in water and in aqueous solution boron atom completes its octet by accepting OH - from water molecules:

B(OH) 3 + 2H 2 O [B(OH) 4 ] - + H 3 O + (ii) Only T1

3+ acts as an oxidising agent on account of inert pair effect.

(iii) In the solid state, the B(OH) 3 units are hydrogen bonded together into two dimensional sheets with almost hexagonal symmetry.

(iv) B(OEt) 3 imparts green colour to the burner flame.