The Laughing Gas

Nitrous Oxide is one of the important oxides of nitrogen which is commonly known as the Laughing Gas. Its molecular formula is N₂O. It is a colourless gas but has a pleasant smell. It is heavier than air and is fairly soluble in cold water and is insoluble in hot water.

When inhaled in prescribed amounts it produces euphoric effect; however when inhaled more than the prescribed amount it could even be fatal. Because of this euphoric laugh it induces it is used as an anaesthetic.

Nitrous Oxide can be assumed to be the anhydride of hyponitrous acid (H₂N₂O₂). But, when dissolved in water N₂O does not produce H₂N₂O₂. It is a neutral oxide and hence is neutral to litmus.

Nitrous Oxide is prepared by the reaction between NH₄SO₄ and NaNO₃ at a temperature below 240°C. NH₄SO₄ and NaNO₃ react together to form NH₄NO₃ which on heating decomposes to produce N₂O and H₂O. 

The reactions are as follows;

NH₄SO₄ + NaNO₃ ® NaSO₄ + NH₄NO₃

NH₄NO₃ ® N₂O + H₂O

N₂O when heated above 500°C decomposes into N₂ and O₂. Thus it supports combustion of Sulphur and Phosphorus turning them into SO₂ and P₂O₅ respectively. It also converts Cu into CuO. While converting these elements into their oxides, N₂O gets itself converted into N₂.

The structure of N₂O is as follows;