Answer the question on basis of passage given below:

P block elements are placed in groups 13 to 18 of the periodic table. Their valence shell electronic configuration is \(ns^2\, \ np^{1-6}\). Group 16 of of the p-block elements are known as the group of chalcogens having \(ns^2\, \ np^4\) as their general electronic configuration. They exhibit number of oxidation states but the stability of \(-2\) oxidation state decreases down the group. They are sometimes also known as group of chalcogens as the name is derived from the Greek word for brass and points to the association of sulphur and its congeners with copper. Their ionization enthalpy decreases down the group. Oxygen shows anomalous behaviour due to its small size and high electronegativity.

Match the oxidation state of phosphorus in the following compounds to their counter parts in List II

Choose the current 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 explain how to determine the oxidation state of phosphorus in each of the given compounds and match them accordingly.

Oxidation States Calculation

A. \(H_3PO_2\) (Hypophosphorous Acid)

Molecular Formula: \(H_3PO_2\)

Oxidation States:

Hydrogen (\(H\)) is +1.

Oxygen (\(O\)) is -2.

Let \(x\) be the oxidation state of phosphorus (P).

\(3(\text{H}) + x (\text{P}) + 2 (\text{O}) = 0\)

\(3(+1) + x + 2(-2) = 0\)

\(3 + x - 4 = 0\)

\(x = +1\)

I +1

B. \(H_4P_2O_6\) (Phosphorous Acid)

Molecular Formula: \(H_4P_2O_6\)

Oxidation States:

Hydrogen (\(H\)) is +1.

Oxygen (\(O\)) is -2.

Let \(x\) be the oxidation state of phosphorus (P).

\(4(\text{H}) + 2x (\text{P}) + 6 (\text{O}) = 0\)

\(4(+1) + 2x + 6(-2) = 0\)

\(4 + 2x - 12 = 0\)

\(2x - 8 = 0\)

\(2x = +8\)

\(x = +4\)

Oxidation State of Phosphorus: +4

C. \(H_3PO_3\) (Phosphorous Acid)

Molecular Formula: \(H_3PO_3\)

Oxidation States:

Hydrogen (\(H\)) is +1.

Oxygen (\(O\)) is -2.

Let \(x\) be the oxidation state of phosphorus (P).

\(3(\text{H}) + x (\text{P}) + 3 (\text{O}) = 0\)

\(3(+1) + x + 3(-2) = 0\)

\(3 + x - 6 = 0\)

\(x = +3\)

Oxidation State of Phosphorus: +3

D. \(H_3PO_4\) (Phosphoric Acid)

Molecular Formula: \(H_3PO_4\)

Oxidation States:

Hydrogen (\(H\)) is +1.

Oxygen (\(O\)) is -2.

Let \(x\) be the oxidation state of phosphorus (P).

\(3(\text{H}) + x (\text{P}) + 4 (\text{O}) = 0\)

\(3(+1) + x + 4(-2) = 0\)

\(3 + x - 8 = 0\)

\(x = +5\)

Oxidation State of Phosphorus: +5

The matches are: 1. A-III, B-IV, C-I, D-II