CORROSION

 Metals when exposed in the atmosphere, it will react with substances around it such as moisture, air, acid etc. Such reactions led to loss of its shining appearance and become corrode. This process is known as corrosion.

Examples of corrosion 

1. Rusting of iron 

Iron when exposed to atmospheric oxygen and water for long periods resulted in formation of a brown coloured substance on it surface. That brown coloured substance is known as rust. This process is called rusting of iron. Rusting of iron is redox reaction 

Iron react with oxygen and water to produce oxides of iron

4Fe + 3O₂ + 2H₂O—> 2Fe₂O₃.H₂O

Rusting of iron can be prevented by coating iron with paint, grease or oil, galvanisation etc to prevent direct contact with oxygen and water.

2. Tarnishing of copper ( green coloured coating in copper )

When copper exposed to atmosphere for long period, it will react with water, carbon dioxide and oxygen to produce copper carbonate on it surface resulted in the formation of green coloured coating.

Reaction is:

Cu + H₂O +CO₂+O—> CuCO₃ . Cu(OH)₂

3. Tarnishing of silver ( Black coating of silver )

When silver exposed to atmosphere, it will react with sulfur or sulfur compounds and produce silver sulphide (Ag₂S)which is black in colour 

Reaction is:

4Ag + 2H₂S + O₂ —> 2Ag₂S + 2H₂0












OUR YOUTUBE CHANNEL

OUR YOUTUBE CHANNEL

Most viewed

WORKING MODEL FOR SCIENCE EXHIBITION- DANCING BALLOON

Image
 DANCING BALLOON  SCIENCE EXHIBITION PROJECT FOR HIGH SCHOOL STUDENTS  A working model for science exhibition ‘THE DANCING BALLOON’ is an application of Newton’s third law of motion- Every action has an equal and opposite reaction and also explains about effect of less friction helps in the motion of a body. MATERIALS REQUIRED  1- Balloon  2- Compact disk (CD) 3- Glue 4- Bottle cap PROCEDURE  *Put a hole on bottle cap(at the centre)  * Using glue stick the bottle cap at the top of CD (cap should be fixed on rough and non shiny surface of CD . Make sure no gap between CD ad the bottle cap) * Keep it aside still glue dries up to make strong bond between CD and bottle cap * Inflate the ballon and fix it on bottle cap as shown in video  * And keep CD on plane surface and release it. RESULT Balloon/CD arrangement start moving around the plain surface automatically . SCIENTIFIC EXPLANATION  Due to the force applied by the air inside the balloon it ...
Read more
Image
This blog contents are specifically for high school students all over the world . Those who are preparing for GCSE physics and GCSE chemistry have lot of topic to refer from this blog. PHYSICS   CHEMISTRY   SCIENCE IN DAILY LIFE  SCIENCE EXHIBITION PROJECTS 
Read more

ELECTRIC CHARGES

Image
TYPE OF CHARGES  There are two type of electric charges, positive charge (+) and negative charge(-) PROPERTIES OF ELECTRIC CHARGES Unlike charges, always attract each other.  Positive charge kept near negative charge/ negative charge kept near positive charge, attract each other. Like charges always repel each other.  Positive charge kept near positive charge / negative charge kept near negative charge, repel each other. PRESENCE OF CHARGE IN MATTER All the materials around as are generally known as matters (matter is anything that can occupy space and have mass). All the matters are made up of tiny building unites called atoms. Atoms are made up of some small subatomic particles – electrons, protons, neutrons. The centre part of the atom is known as nuclear , which contain protons and neutrons . Protons are positively charged particles and neutrons are chargeless particle (neutral). And electrons which are revolving around the nuclear of an atom in fixed orbits has neg...
Read more

MAGNETS

Image
Magnets are substances which can attract some materials like iron, steel, nickel etc.  Different types of magnets  Based on shape of the magnets we can classify magnets into different names. Pictures and names of som magnets are given below                   A magnet always has 2 poles a north pole and a south pole ( when a magnet is cut into two pieces, the new pieces formed will act as separate magnets with a north pole and south pole for each                                     
Read more