Priestley first made nitrous oxide gas in 1772 and Devi studied its properties. Smelling this gas causes laughter. For this reason, it is also called laughing gas.

Preparation:

Oxidation of hydroxylamine

nitrous oxide is obtained by oxidizing hydroxylamine salts with Sodium nitrite, copper sulfate, potassium permanganate or ferric chloride.

NH₂OH.HCl + NaNO₂ → NaCl + 2H₂O + N₂O

Reduction of nitric acid

reduction of HNO₃ by stannic chloride (SnCl₄) and HCl gives nitrous oxidation.

4SnCl₂ + 8HCl + 2HNO₃ → 4SnCl₄ + 5H₂O + N₂O

Dilute HNO₃

when cold and the molecule HNO₃ reacts with Zn, N₂O is obtained.

4Zn + 10HNO₃ → 4Zn(NO₃)₂ + 5H₂O + N₂O

Heating ammonia nitrate

Nitrous oxide is obtained by heating ammonia nitrate. On heating the ammonia nitrate alone, it melts at 165⁰C, starts to decompose at 185⁰C and starts exploding at 240⁰C. In the laboratory, nitrous oxide gas was first created by heating a mixture of ammonia sulfate and ammonia nitrate. The ammonia nitrate obtained from the mixture does not explode and Nitrous oxide gas is obtained.

(NH₄)₂SO₄ + 2NaNO₃ → Na₂SO₄ + 2NH₄NO₃

NH₄NO₃ → N₂O + 2H₂O

Ammonia chloride and ammonia nitrate doing the same reactions:

NH₄Cl + NaNO₃ → NaCl + NH₄NO₃

NH₄NO₃ → N₂O + 2H₂O

Laboratory method:

In the laboratory, the flask is heated by mixing a mixture of sodium nitrate and ammonia sulfate. The obtained nitrous oxide gas is affected by KOH, FeSO4 and concentrated sulfuric acid. Which removes impurities of chlorine, nitric oxide and ammonia respectively. N2O collects gas in hot water. Because it is soluble in cold water.

2KOH + Cl₂ → KCl + KClO + H₂O

2NaOH + Cl₂ → NaCl + NaClO + H₂O

FeSO₄ + NO → FeSO₄.NO

2NH₃ + H₂SO₄ → (NH₄)2SO₄

Physical Properties:

This colorless sweet taste has gas. It is a fusion of water and alcohol. Its smell causes laughter. The smell in excess makes the man unconscious. And can also die of the throat.

Chemical Properties:

It has no effect on litmus. Hence it is indifferent.

On heating, it gives nitrogen and oxygen.

2N₂O → 2N₂ + O₂

It gives oxygen on heating. Therefore, it helps in burning things like oxygen.

S + 2N₂O → 2N₂ + SO₂

C + 2N₂O → 2N₂ + CO₂

2P + 5N₂O → 5N₂ + P₂O₅

It dissipates when flowing over hot copper.

Cu + N₂O → N₂ + CuO

Use of N₂O

Nitrous Oxide uses for especially in surgery and dentistry.

Structure:

The molecular formula of Nitrous Oxide is N₂O and the structure is like this:

N ≡ N → O

The nitrogen atoms in nitrous oxide are sp hybridized and it is a linear molecule. Nitrous oxide is a polar co-ordinate molecule and its two-pole base must be higher, in fact, its double pole base is very useful. For this reason, it is assumed that it is a resonant hybrid of the following two structures.