Review the key concepts, formulae, and examples before starting your quiz.
🔑Concepts
Neutralisation is a chemical reaction between an acid and a base, resulting in the formation of salt and water along with the evolution of heat.
The reaction can be represented as:
In daily life, neutralisation is used to treat indigestion caused by excess (Hydrochloric acid) in the stomach using antacids like Milk of Magnesia .
Ant stings contain formic acid. The effect of the sting can be neutralised by rubbing moist baking soda (sodium hydrogen carbonate, ) or calamine solution, which contains zinc carbonate ().
Soil treatment: If the soil is too acidic, it is treated with bases like quick lime () or slaked lime (). If the soil is basic, organic matter is added as it releases acids to neutralise the base.
Factory wastes are often acidic and can kill fish and other organisms. They are neutralised by adding basic substances before being discharged into water bodies.
📐Formulae
💡Examples
Problem 1:
An ant bites a person and causes a burning sensation. What substance can be applied to provide relief, and why?
Solution:
Moist baking soda () or calamine solution () should be applied.
Explanation:
The ant sting injects acidic liquid (formic acid) into the skin. Baking soda and calamine are basic in nature. Applying them leads to a neutralisation reaction: , which cancels the effect of the acid.
Problem 2:
Why are antacids taken when we suffer from acidity/indigestion?
Solution:
Antacids contain bases like magnesium hydroxide ().
Explanation:
Our stomach produces to digest food. Excess causes indigestion. The base in the antacid neutralises the excess acid, forming salt and water, thereby providing relief.
Problem 3:
How is acidic soil treated to make it suitable for plant growth?
Solution:
Acidic soil is treated with quick lime () or slaked lime ().
Explanation:
Plants do not grow well when the soil is too acidic. Adding a base like or neutralises the excess acids present in the soil, making the level neutral and suitable for vegetation.