NTA Abhyas JEE Main2020Chemistryp Block Elements (Group 13 & 14)Practice
Which one of the following is the correct statement?
Options
- ABoric acid is a protonic acid.
- BBoth T i 3 + a n d A l 3 + ions act as oxidising agent in aqueous solution.
- CHydrogen bonding in H 3 B O 3 gives it a layered structure.
- DB O E t 3 imparts blue colour to the burner flamer.
Correct answer
C. Hydrogen bonding in H 3 B O 3 gives it a layered structure.
Step-by-step solution
(i) It is a weak monobasic acid soluble in water and in aqueous solution boron atom completes its octet by accepting O H – from water molecules: B O H 3 + 2 H 2 O → B O H 4 - + H 3 O + (ii) Only T l 3 + acts as an oxidising agent on account of inert pair effect. (iii) In the solid state, the B O H 3 units are hydrogen bonded together into two dimensional sheets with almost hexagonal symmetry. (iv) B O E t 3 imparts green colour to the burner flame.