Question

Write the properties of chemical reaction.

Answer 1

Properties of chemical reaction

• Iron reacts with oxygen and moisture present in the air, forms the iron oxide (rust).
• Production of gas: When fuel like petrol, kerosene etc are burnt then carbon present in them reacts with air and forms (CO₂ ) carbon dioxide in the same manner CO₂ is produced when coal is burnt. C + O → CO₂ (gas)
• When sulphuric acid is poured slowly in a test tube in granulated zinc, hydrogen gas is produced. If a burning matchstick is taken at the mouth of the test tube it burns with an explosion.
• Change in colour: Colour of cut apple is changed because iron present in apple reacts with oxygen present in the air and form iron oxide.
• Change of heat: When ammonium chloride is put in water it becomes cold.
• Dissolution: In hard water, soap does not form foams but produces white undissolved substance.