How can we classify equations into endothermic and exothermic reactions just by looking at it?

Asked by minnumurali13 | 9th May, 2020, 12:56: PM

Expert Answer:

To determine whether the reaction is exothermic or endothermic only by looking at the reaction, following method will be helpfull:
 
If the reaction is Exothermic, the term- 'Heat' or 'Δ' sign will be written on the product side (R.H.S.).
 
If the reaction is Endothermic, the term- 'Heat' or 'Δ' sign will be written on the reactant side (L.H.S.).
 
For example:
 

Exothermic reaction

The chemical reactions which proceed with the evolution of heat energy are called as exothermic reactions.

A  +  B  →  C  +  Δ


For example:

2SO2  +  O2  2SO+  Δ

CaO  +  H2O  →  Ca(OH)2  +  Δ

Endothermic reactions

The chemical reactions which proceed with the absorption of heat energy are called as exothermic reactions.

A  +  B  +  Δ   →  C 

 

For example:

C  +  H2O  +  Δ  →  CO  +   H2

N2  +  O2  +  Δ     2NO

Answered by Ramandeep | 9th May, 2020, 07:08: PM

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