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 .

in the analysis of systems that involve fluid flow, we frequently encounter the combination of properties u and pv.