To study decomposition reactions.
What is a decomposition reaction?
Decomposition is a type of chemical reaction. It is defined as the reaction in which a single compound splits into two or more simple substances under suitable conditions. It is just the opposite of the combination reaction.
In a combination reaction, a substance is formed as a result of chemical combination, while in a decomposition reaction, the substance breaks into new substances.
For example: The digestion of food in our body is accompanied by a number of decomposition reactions. The major constituents of our food such as carbohydrates, fats proteins, etc., decompose to form a number of simpler substances. These substances further react, releasing large amounts of energy, which keeps our body working.
The general equation that describes a decomposition reaction is:
Types of Decomposition Reactions
Decomposition reactions can be classified into three types:
- Thermal decomposition reaction
- Electrolytic decomposition reaction
- Photo decomposition reaction
Thermal decomposition is a chemical reaction where a single substance breaks into two or more simple substances when heated. The reaction is usually endothermic because heat is required to break the bonds present in the substance.
Photo decomposition is a chemical reaction in which a substance is broken down into simple substances by exposure to light (photons).
Why are decomposition reactions mostly endothermic in nature?
Most decomposition reactions require energy either in the form of heat, light or electricity. Absorption of energy causes the breaking of the bonds present in the reacting substance which decomposes to give the product.
- Students understand the characteristics of a decomposition reaction & different types of such reactions.
- Students identify the compounds that may give a decomposition reaction.
- Students acquire skills to perform a decomposition reaction in the lab.
- Students will be able to distinguish a decomposition reaction from a given set of chemical reactions.
Let’s discuss the decomposition reaction of ferrous sulphate crystals by the action of heat.