The molecules has kinetic energy and potential energy both. When the water molecules were heated on a Bunsen Burner then there can be a slight increase in the volume of the water.
This is because upon heating the kinetic energy of the molecules increases and it starts moving fastly.
Due to the movement of the particles, they become far from each other and there is a slight increase in the volume of the water.
Chemical equilibrium is reached by the forward reaction rate equaling the reverse reaction rate. If the reaction is not reversible, this could not occur.
Imagine a chemist is in the lab and trying to make some chemical reactions happen. In one reaction she reacts chemicals in an exothermic reaction and there is an increase in entropy. A second chemical reaction she is trying to run is endothermic and there is a decrease in entropy. Which of the two reactions is more likely to occur and why?
