Question

how is hydrogen gas prepared in the laboratory ?how is it collected? give give chemical equation for the reaction.

Answer 1

Hydrogen gas is prepared in laboratory by the action of dilute HCl upon granulated zinc.

Zn+dil⋅H2SO4⟶ZnSO4(aq)+H2↑



Procedure:

The granulated zinc pieces are taken in a Woulfe’s bottle and the apparatus is fitted as shown in figure. The two necks of woulfe’s bottle is tighten up with cork so that no air enters from outside. It is connected with the delivery tube to a water trough containing water. Dilute sulphuric acid is poured slowly from the thistle funnel. Some crystals of copper sulphate are added to increase the rate of reaction. The hydrogen gas thus formed is collected in a gas jar through delivery tube by the downward displacement of water.


Purification: The hydrogen gas thus obtained may contain different impurities like H2S, NO2, CO2, moisture etc. So, these impurities are removed by using suitable process to get pure hydrogen.



Hope this helpssssssss......
;)

Answer 2

Hydrogen gas is prepared in laboratory in the following way -

• Required materials :

- Zinc Granules.

- Diluted Sulphuric Acid.

• At first,the zinc granules are added in the aqueous solution of the diluted sulphuric acid.

• Then after sometime,they react with each other in order to form zinc sulfate and hydrogen gas,as the main products of the chemical reaction.

•The evolved hydrogen gas is easily collected by the downward displacement of the water method.

• The chemical equation of the given chemical reaction is :

Zn + H2SO4 = ZnSO4 + H2 (g)