Question

In the lab preparation of hydrogen, answer the following: i. Reactant used ii. Products formed iii. Precautions taken iv. Collection of gas v. Impurities present vi. Balanced equation​

Answer 1

Answer:

Reactant used -

Hydrogen is prepared in the laboratory by the action of the dilute hydrochloric acid or dilute sulphuric acid on granulated zinc. Use of Granulated Zinc

Precautions taken -

1.Apparatus should be use tight.

2.Allow the first few bubbles of hydrogen gas to escape, as they not only contain air, but also form an explosive mixture.

3.Don't bring any naked flame near the apparatus.

4.The lower end of thistle funnel must dip in the dilute sulphuric acid, as otherwise gas will escape from the thistle funnel.

Collection of gas-

Hydrogen gas is prepared in laboratory by the action of dilute HCl upon granulated zinc. ... The hydrogen gas thus formed is collected in a gas jar through delivery tube by the downward displacement of water.

Impurities present -

Purification: The hydrogen gas thus obtained may contain different impurities like H2S, NO2, CO2, moisture etc.

Balanced equation-

In the laboratory, H2 is usually prepared by the reaction of acids on metals such as zinc with Kip's apparatus. The electrolysis of water is a simple method of producing hydrogen. A low voltage current is run through the water, and gaseous oxygen forms at the anode while gaseous hydrogen forms at the cathode.