LECTURE -3 : CLASS VIII : SCIENCE : CHAPTER 4 : DISPLACEMENT REACTIONS AND USES OF METALS AND NON-METALS

 CLASS VIII   |    SCIENCE    |    CHAPTER 4: 

METALS AND NON-METALS

      Notes prepared by Subhankar Karmakar

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• A more reactive metal displaces a less reactive metal from its salt solution. 
• When a more reactive metal is placed in a salt solution of a less reactive metal, then the more reactive metal metal displaces the less reactive metal from its salt solution.
• A displacement reaction, also known as a replacement reaction, is a type of chemical reaction in which one element replaces another in a compound.
• This type of reaction occurs when a more reactive element replaces a less reactive element in a compound.
• The displaced element is released as a free element, and the newly formed compound contains the element that did the displacing.
• Displacement reactions are often used to extract metals from their ores, and they are also important in organic chemistry reactions.
• One common example of a displacement reaction is the reaction of iron with copper sulfate to form iron sulfate and copper.

Example, Reaction of Iron Metal with Copper Sulphate solution: 

Copper Sulphate + Iron → Iron Sulphate + Copper 

CuSO₄ + Fe → FeSO₄ + Cu

METALS	NON-METALS
1.      1.    Metals form basic oxides.	1.    Non-metals form acidic oxides
2.       2.  Most metals react with water (or steam) to produce Hydrogen gas.	2.    Non-metals do not react with water.
3.      3.  Metals react with dilute acids to produce Hydrogen gas.	3.    Non metals do not react with dilute acids.

USES OF METALS:

Some of the most uses of metals are given below : 

1: Iron, copper, and Aluminium metals are used to make cooking utensils and water boilers for factories.

2: Copper metal is used for making electric wires for household wiring, electric motors, armature of dynamos, and many other electrical appliances. Aluminium metal is used for making electric cables and over-head electric transmission lines. 

3. Aluminium foils are used for packaging medicines, chocolates, food items, and many other materials. 

4. Aluminium metal in the form of alloys is used to make aeroplanes. 

USES OF NON-METALS:

Non-metals have many important uses in our daily lives. Here are some examples:

1. Oxygen (O) is a non-metal that is essential for life. It makes up about 21% of the air we breathe and is used by living organisms to produce energy through respiration.
2. Nitrogen (N) is another non-metal that makes up about 78% of the air we breathe. It is used in the production of fertilizers and as a coolant in certain industrial processes.
3. Carbon (C) is a non-metal that is found in all living organisms. It is used in the production of fuels, such as coal and oil, and is also used in the manufacturing of various products, including plastics, rubber, and textiles.
4. Chlorine (Cl) is a non-metal that is used as a disinfectant in swimming pools and water treatment plants. It is also used in the production of various chemicals, including PVC plastics.
5. Hydrogen (H) is a non-metal that is used as a fuel in vehicles and as a source of energy in fuel cells. It is also used in the production of ammonia, which is used in the production of fertilizers.
6. Sulfur (S) is a non-metal that is used in the production of sulfuric acid, which is a key component in the production of many chemicals and fertilizers. It is also used in the production of rubber and as a fungicide in agriculture.