Question

why are decomposition reactions considered as opposite of combination reactions? justify your answer with three valid points giving suitable examples in tabular column.

Answer 1

1) In a decomposition reaction, 1 reactant= multiple products but in combination reaction 2 or more products are formed from one reactant/element.

2) Decomposition reactions are mostly endothermic(absorb energy) while combination reactions are widely exothermic( release heat).

3) Decomposition reactions break down (decompose) elements in reactant side whereas combination reactions combine elements in reactant side.