Question

Which of the following is correct for P4 molecule of white phosphorus?
(i) It has 6 lone pairs of electrons.
(ii) It has six P-P single bonds.
(iii) It has three P-P single bonds.
(iv) It has four lone pairs of electrons.


NCERT Class XII
Chemistry - Exemplar Problems

Chapter 7. The p-block elements

Answer 1

(ii) It has six P-P single bonds. (iv)it has four lone pair of electrons

Answer 2

Answer: Option (ii) and (iv) are correct.

Explanation:

Structure of a $P_{4}$ molecule of white phosphorus has a tetrahedral geometry.

As valency of phosphorus is 5 and there are in total four phosphorus atoms. Hence, there will be 4 × 5 = 20 valence electrons.

Hence, each P atom has one lone pair of electron and each covalent bond (includes two electrons) will be formed.

Therefore, in total there will be 4 lone pair of electrons and six P-P single bonds in a $P_{4}$ molecule of white phosphorus.