Final answer:
An exothermic reaction with increased entropy is always spontaneous, as this combination generally results in a negative change in Gibbs free energy, indicative of a spontaneous process.
Step-by-step explanation:
The chemical reaction that will always be spontaneous is an exothermic reaction in which entropy increases. Spontaneity in chemical processes depends on the Gibbs free energy change (ΔG), which considers both entropy (disorder) and enthalpy (heat energy). An exothermic reaction releases heat, and when combined with an increase in entropy (disorder), it generally leads to a negative ΔG, indicating a spontaneous process. For instance, the dissolution of salt in water is a spontaneous process where heat is released, and the disorder increases as solid salt disperses in the solvent.