Which of the following chemical reactions is always endothermic in nature?

Question

Question

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NTPC Tier I (Held On: 29 Apr 2016 Shift 2)

Answer 1

Option 2 is the correct answer: Decomposition reactions are always endothermic in nature.

In a decomposition reaction, a chemical compound is broken into its constituent components.
The process takes place through the breaking of bonds between the constituent atoms of the compound.
The reaction in which heat or light energy is absorbed during the process, are called endothermic reactions.
In decomposition reactions, the energy is required to break the chemical bonds. therefore they are aways endothermic in nature.
Combustion reaction - Combustion means reaction with oxygen, hence combustion reactions are generally oxidation reactions (Exothermic).
Displacement reaction - One constituent component is replaced by some other component (Spontaneous and exothermic).
Combination reaction - Two or more elements or compounds combine. New bonds are formed and energy is released (Exothermic).