Match List I with List II

Choose the correct answer from the options given below:

A-III, B-IV, C-I, D-II

The correct answer is option 1. A-III, B-IV, C-I, D-II

Let us go through the structure and bonding of each oxoacid of phosphorus in detail to understand the correct matching of bonds.

(A) \( H_3PO_2 \) (Hypophosphorous Acid)

The molecular structure of \( H_3PO_2 \) can be represented as:

Bond Analysis:

P-H bonds: There are 2 P-H bonds (directly attached to phosphorus).

P-OH bond: There is 1 P-OH bond.

P=O bond: There is 1 P=O double bond.

Total number of bonds: Adding these up, the total number of characteristic bonds in \( H_3PO_2 \) is:

\(2 (\text{P-H}) + 1 (\text{P-OH}) + 1 (\text{P=O}) = 4 \text{ bonds}\)

Match: \( H_3PO_2 \) → 4 bonds (III)

(B) \( H_4P_2O_5 \) (Pyrophosphorous Acid)

The molecular structure of \( H_4P_2O_5 \) is:

Bond Analysis:

P-H bonds: There are 2 P-H bonds in this molecule.

P-OH bonds: There are 2 P-OH bonds.

P=O bonds: There are 2 P=O double bonds.

Total number of bonds: Adding these up, the total number of characteristic bonds in \( H_4P_2O_5 \) is:

\(2 (\text{P-OH}) + 2 (\text{P=O}) + 2 (\text{P-H}) = 6 \text{ bonds}\)

Match: \( H_4P_2O_5 \) → 6 bonds (IV).

(C) \( H_4P_2O_6 \) (Hypophosphoric Acid)

The molecular structure of \( H_4P_2O_6 \) is:

Bond Analysis:

P-H bonds: There are no P-H bonds in this molecule.

P-OH bonds: There are 4 P-OH bonds.

P=O bonds: There are 2 P=O double bonds.

P-O-P bond: There is 1 P-O-P bond.

Total number of bonds: Adding these up, the total number of characteristic bonds in \( H_4P_2O_6 \) is

\(4 (\text{P-OH}) + 2 (\text{P=O}) + 1 (\text{P-O-P}) = 7 \text{ bonds}\)

Match: \( H_4P_2O_6 \) → 7 bonds (I).

(D) \( (HPO_3)_3 \) (Metaphosphoric Acid)

\( (HPO_3)_3 \) is a cyclic trimer, with the structure:

Bond Analysis:

P-H bonds: There are no P-H bonds.

P-OH bonds: There are 3 P-OH bonds (one in each \( HPO_3 \) unit).

P=O bonds: There are 3 P=O double bonds (one in each \( HPO_3 \) unit).

O-H bonds : There are three O-H bonds

OThere are 3 P-O-P bonds linking the phosphorus atoms in the cyclic structure.

Total number of bonds: Adding these up, the total number of characteristic bonds in \( (HPO_3)_3 \) is:

\(3 (\text{P-OH}) + 3 (\text{P=O}) + 3 (\text{P-O-P}) + 3 (\text{O-H})= 12 \text{ bonds}\)

Match: \( (HPO_3)_3 \) → 12 bonds (II).

This corresponds to Option 1: A-III, B-IV, C-I, D-II.