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:-
Answer & explanation
Correct answer: option 2
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.