Why is a rotting apple a reaction in which energy is neither absorbed nor released?

Answer : The correct answer is due to oxidation.

Rotting of apple is a reaction but it neither absorb or release energy because there occur oxidation of inner pulp.

Oxidation is type of reaction which take place in presence of oxygen in which oxygen reduces itself to oxidize the other substance or loss of electrons from an substance. Oxidation reaction neither releases energy nor they absorb energy.

So when apple is kept outside and the outer skin cells of it died, the oxygen present in surrounding environment oxidizes the inner pulp and decaying of it.

Hence we can say rotting of apple doe not involve any energy exchange.

Rotting of an apple is a reaction in which energy is neither absorbed nor released because it is not an endothermic or exothermic reaction but an enzyme catalysed oxidation reaction.

Explanation:

The discoloration of apple is an oxidation reaction catalysed by enzymes. The phenolic compounds such as monohydroxy and dihydroxyphenol get oxidized by enzymes present in the apple in the presence of environmental oxygen causing the discoloration of apple. Enzyme catalysed oxidation reaction is not an endothermic or exothermic reaction.

In an endothermic reaction heat is absorbed by the system and in an exothermic reaction heat is released by the system.