Question 1 What is meant by chemical reaction. Give one example of Chemical reactions?
Question 2 What are reactants?
Question 3 What are products?
Question 4 Why should magnesium ribbon be cleaned before burning in air?
Chemical Reaction and Equation
Chemical reactions are the processes in which new substance with new properties are formed.
Only a rearrangement of atoms takes place in a chemical reaction.
The substances which take part in a chemical reaction are called reactants.
The new substances produced as a result of chemical reaction are called products.
Magnesium + oxygen → Magnesium oxide
Magnesium(ribbon), oxygen(gas) → Reactants
Magnesium Oxide(White powder, dazzling white flame) → Product
When magnesium ribbon is heated, it burns in air with a dazzling white flame to form white powder called magnesium oxide.
The magnesium ribbon which we use usually has a coating of basic magnesium carbonate on its surface which is formed by slow action of moist air on it. Before burning in air, the magnesium ribbon is cleaned by rubbing with a sand paper. This is done to remove protective layer of basic magnesium carbonate from the surface of magnesium ribbon so that it readily combine with the oxygen of air.
Examples of Chemical Reaction in daily Life:
Formation of curd from milk, cooking of food, digestion of food, process of respiration, fermentation of grapes, rusting of iron, burning of fuel, ripening of fruits, burning of candle wax etc.
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