Answer the question on the basis of passage given below:

Nitrogen forms a large number of oxoacids such as $H_2N_2O_2$, (hyponitrous acid), $HNO_2$, (nitrous acid) and $HNO_3$, (nitric acid). Amongst these, $HNO_3$, is the most important. It is used in the manufacture of ammonium nitrate for fertilisers and other nitrates for use in explosives. It is also used to prepare many important organo-nitro compounds like nitroglycerine, trinitrotoluene etc. It acts as a strong oxidizing agent and used as an oxidiser in rocket fuels.

The covalency and oxidation state of nitrogen in $HNO_3$, are:-

four and +5, respectively

The correct answer is Option (2) → four and +5, respectively.

Covalency of Nitrogen

Bonding: In HNO₃, nitrogen forms:

One double bond with one oxygen atom.

Two single bonds: one with another oxygen and one with a hydroxyl group (OH).

Thus, nitrogen forms a total of four bonds (two single and one double bond). Therefore, the covalency of nitrogen is four.

Oxidation State of Nitrogen

Assign oxidation states as follows:

H: +1

O: -2

For the nitrogen (N), we set up the equation based on the neutrality of the compound:

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

This simplifies to:

\(x + 1 - 6 = 0 \)

\(⇒ x - 5 = 0 \)

\(⇒ x = +5\)

Thus, the oxidation state of nitrogen in \(HNO_3\) is indeed +5.

Conclusion

Covalency: 4

Oxidation State: +5

Therefore, the answer should be four and +5, aligning with your correction.