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Sunday, 19 November 2017

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Chemistry: What is Hydrogen? It's Uses, physical properties, chemical properties and methods of preparation



Hydrogen


Hydrogen is found in group one of the periodic table. Though, it is non-metal, it is usually placed in group one because it has one valence electron.

PERIODIC TABLE HYDROGEN



Physical Properties of Hydrogen
  •  It is a colourless, odourless and tasteless gas.
  • It is neutral to litmus paper.
  • It is insoluble in water.
  • It is the lightest substance known.
  • It has a very low boiling point of (-253-degree Celsius).
  • It is less dense than air.


Chemical Properties of Hydrogen


     1. It reacts with metals to found hydrides.

              
             2Na + H2 ---> 2NaH

     2. It burns in air to produce steam.
    
             H2O + O2 ---> 2H2O

    3. It reacts with halogens to produce halides

            H2 + Cl ---> 2Hcl
            H2 + 2Br ---> 2HBr

   4. Acts as a Reducing agent: It reduces oxides to their respective metals
  
           CuO + H2 ---> Cu + H2O


Uses of hydrogen
  • It is used in the hydrogenation of oil.
  • It is used to manufacture soap and margarine (saponification).
  • It is used in filling balloons.
  • Liquid hydrogen is used for rocket fuel.
  • It is used for welding metals.


Isotopes of hydrogen

Hydrogen has three naturally occurring Isotopes. There are;
  • Protium – ( 11H )
  • Deuterium – ( 12H )
  • Tritium - ( 13H )
“Deuterium oxide” is commonly known as heavy water because it is about 1.1 times heavier than water.  “Protium” has no neutrons, it is the ordinary isotope of hydrogen. “Tritium” is radioactive and rarely found in ordinary hydrogen.

TRITIUM


Read more about: Isotopes and isotopy (chemistry)


Laboratory Preparation of hydrogen

Hydrogen can be prepared in the laboratory by;

* Action of dilute acid on metal.
* Action of cold water on sodium.
* Action of steam on red hot iron


Laboratory preparation of hydrogen by the action of dilute acid on metal.

AIM – To prepare hydrogen.                                                                      

APPARATUS – Round bottom flasks, delivery tube, glass jar, thistle funnel, trough etc.

METHOD
  • Place some pieces of zinc metal in a round bottom flasks
  • Set up the apparatus.
HYDROGEN LABORATORY SET UP

  • Add dilute sulfuric acid (H2SO4) to zinc metal through the thistle funnel.
  • Collect the gas formed over water.

OBSERVATION – As soon as the metal effervescence occurs, gas liberated is collected over water.

CONCLUSION – Hydrogen can be prepared in the laboratory




Industrial preparation of hydrogen

Hydrogen can be prepared in large quantities in the industries by the following ways;
  • Water Gas
  • Hydrocarbon
  • Electrolysis


By Water Gas

When steam is passed over red hot coke at a temperature of about 1100 degree Celsius. The mixture of carbon (ii) oxide or hydrogen gas is produced and this is known as water gas.

H2O + C ---> CO + H2

The product obtained is mixed with excess steam and passed over iron(iii)oxide or Uranium (iii) oxide as a catalyst at a temperature of 450 degree Celsius.

During this process, carbon (ii) oxide in water gas is converted to carbon (iv) oxide and the liberation of excess hydrogen.

CO + H2 + H2O ---> CO + H2

Questions? Comment below.
        


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