Question

Explain the method of preparation of hydrogen gas in the laboratory with chemical equation and diagram?

Answer 1

Hint: The laboratory preparation of hydrogen gas involves the reaction of dilute hydrochloric acid on zinc pieces. We need a $500$ ml flask, a delivery tube, a test tube and a thistle funnel to perform this experiment.

Complete step by step solution:
> First of all we will take a few grams of zinc pieces and put them in the flask. Now add dilute Hydrochloric acid to zinc granules with the help of thistle funnel. After addition of dilute $HCl$ to the zinc pieces hydrogen gas will be produced automatically and this gas will be collected with the help of a delivery tube in a container full of water. Hence hydrogen gas is collected by the downward displacement of water.
Chemical equation: $Zn + 2HCl \to ZnC{l_2} + {H_2}$

> Uses and properties of hydrogen gas- Hydrogen gas is used in rocket fuel and in production of other compounds. It is used in welding, hydrogenation of fats and oils. Hydrogen is a diatomic gas. It is a tasteless, flammable and odourless substance .It can be stored in compressed form as a liquid. With the change of temperature, solubility of hydrogen gas in water does not affect it very much.

                                         Laboratory method of preparation of hydrogen gas

Note: Hence hydrogen gas can be prepared in the laboratory with the help of conical flask ,fitted with the delivery tube. In the flask a few grams of granulated zinc are taken then dilute hydrochloric acid is added to the flask and liberated hydrogen gas is collected in an inverted test tube placed in water. Hydrogen gas obtained by this procedure contains different impurities like ${H_2}S,N{O_2},C{O_2}$ and moisture etc.