Why is a reaction reversible?

This reversible reaction can be broken into two reactions. These two reactions are occurring simultaneously, which means that the reactants are reacting to yield the products, as the products are reacting to produce the reactants. Collisions of the reacting molecules cause chemical reactions in a closed system.May 28, 2014 read more

A reaction is said to be reversible if both the reactants and products are in equilibrium with each other . The equilibrium constant K also depends upon the Gibbs enthalpy (G) of the reaction . If change in G is negative , the reaction is feasible . read more

There are several reasons for the reverse reaction to be favored; one is temperature. In the following reaction: $$\ce{2NO_2<=> N_2O_4 + energy}$$ The right is the favored product, unless the temperature is increased. With enough heat, then the reactant is favored. read more

A 'reversible' reaction is one which has an equilibrium constant somewhere in the middle and so changing the concentration of reactants or products has a significant effect on the position of equilibrium. Generally, a reaction where $|\Delta G_\text{rxn}| < 30mathrm{kJ~mol^{-1}}$, can be considered reversible. read more