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Question: In hyponitrous acid, the number of hydroxyl group present are: (A). \(1\) (B). \(2\) (C). \(3\...

In hyponitrous acid, the number of hydroxyl group present are:
(A). 11
(B). 22
(C). 33
(D). 44

Explanation

Solution

There are two possible structure of acid, Tans and cis Trans-Hyponitrous acid forms with crystals that are explosive when dry. In solution, it is a weak acid (PKa1=7.21,PKa2=11.54)\left( {P{K_{a1}} = 7.21,P{K_{a2}} = 11.54} \right) and decomposed to laughing gas and water with a half lifetime of 1616 days at 25∘C25^\circ C at pH 1−31 - 3 .

Complete answer:
Hyponitrous acid is chemical compound with formula H2N2O2{H_2}{N_2}{O_2} or HON=NOHHON = NOH . it is an isomer tautomer of nitramide, H2N−NO2{H_2}N - N{O_2}

The number of hydroxyl groups present are two. The preparation of hyponitrous acid ( trans isomer ) can be done with silver hyponitrite and anhydrous HClHCl in ether.
Ag2N2O2+2HCl→H2N2O2+2AgClA{g_2}{N_2}{O_2} + 2HCl \to {H_2}{N_2}{O_2} + 2AgCl
Ferrous hydroxide will also reduce nitrates to hyponitrites.
Pure ferrous sulphate is precipitated with milk of lime, and to the cooled mixture is added 11 mol of NaNO3NaN{O_3} for each 1010 moles of FeSO4FeS{O_4} . The hyponitrite is precipitated with silver nitrate.
A solution of NaNO2NaN{O_2} is added to an answer of NH2OH−H2SO4N{H_2}OH - {H_2}S{O_4} . The mixture is heated quickly to 60∘C60^\circ C and AgNO3AgN{O_3} is added at once. This method does not give good yields, but it proves that acid may be a dioxime. It proceeds as follows-
HO−NH2+O=N−OH→HO−N=N−OH+H2OHO - N{H_2} + O = N - OH \to HO - N = N - OH + {H_2}O

Therefore, option B is correct.

Additional Information:
Salt of Hyponitrous acid is soluble in water and hydrolyse and gives an alkaline solution . Whereas normal salts of other bases are less soluble .
In the dry state it decomposes at 100∘C100^\circ C , giving AgNO3AgN{O_3} and it explodes at 150∘C150^\circ C .It is not decomposed by alkalies. It reacts with alkyl iodides, giving alkyl hypritrites.

Note:
It was shown by Divers in 18711871 , the sodium nitrate reduced with sodium amalgam gives a salt NaNONaNO (empirical composition) , the acid being an isomer of nitramide.
Since the discovery of hyponitrous acid by Dr. Divers , no new oxyacid of nitrogen has been described .