CHEMY. 4M2.2HYDROGEN

HYDROGEN

Is lightest and the most abandonment element in the universe.

This means it is an element from which the sun and stars are made from.

LABORATORY PREPARATION OF HYDROGEN

Hydrogen can prepared in the laboratory by the following method;

The reaction of dilute hydrochloric acid and with zinc metal. When a zinc reacts with diluted Hydrochloric acid, zinc chloride and Hydrogen gas is produced.

Reaction: Zn_(s) + 2HCl₍₁₎         →   ZnCl_2(aq) + H_2(g)

• Zinc +Hydrochloric acid      →    Zinc chloride + hydrogen gas

Hydrogen is a good reducing agent.

Reducing agent –

Is substance which removes Oxygen from substance.

E.g: metal oxides.

Reduction:

Is the removal of oxygen from substance.

Or

 Is the addition of hydrogen to a substance.

Reaction:

Copper (ii) oxide + hydrogen → copper + water

 CuO_(S) +H_2(g)                  →    Cu_(S) + H2O_(L)    

  

Oxidation:

Is the removal of hydrogen from a substance.

Or

Is the addition of Oxygen to a substance.

Industrial Manufacturing of Hydrogen

In industry the hydrogen gas manufactured by Electrolysis

Electrolysis of Water

Is a process in which an element decompose.

Reaction:

Water → Oxygen + Hydrogen

2H₂0_(L) → 0_2(g) + 2H_2(g)

Physical Properties of Hydrogen

1. It's tasteless, colourless and odorless.

2. It's lighter than air, Therefore it is in the atmosphere.

3. It's only slightly soluble in water.

4. It's does not support combustion.

Chemical properties of Hydrogen

1. It combine easily with other chemicals substance at high temperature.

2. It does not usually react with other element at room temperature.

3. It is highly flammable and burns with a blue of flame.

4. It reacts slowly with oxygen to produce water.

5. It is neither acidic nor basic.

2. It does not usually react with other element at room temperature.

3. It is highly flammable and burns with a blue of flame.

4. It reacts slowly with oxygen to produce water.

5. It is neither acidic nor basic.

Uses of Hydrogen

      I.        Manufacture of ammonia: Hydrogen is used in the synthesis ammonia by reacting it with nitrogen in the presence of an iron. This is done on large scale through the laboratory

    II.        process.

   III.        Manufacture of Margarine : Hydrogen is used in the Manufacture of margarine.

  IV.        Oxy-hydrogen flame: Hydrogen is used to produce oxy-hydrogen flame. This flame can be used for welding and cutting metal.

   V.        Fuel : Since hydrogen is highly flammable, especially when mixed with pure oxygen, it is used as a fuel in rockets. Usually they combine liquid hydrogen with liquid oxygen to

  VI.        make an explosive mixture.

REVIEW QUESTION

1 (a) By the aid of diagram explain preparation of hydrogen using zinc and dilute hydrochloric acid.

(b) Give the properties and uses of hydrogen.