Answer the following question given this paragraph: 

Chemists want to be able to predict the outcome of reactions. They would like it to be possible to predict what will happen when reactants are added together under a given set of conditions. The conditions of a reaction might include things like temperature, pressure, and concentrations of various reaction components. If the given conditions favor the formation of products, the reaction is said to be spontaneous .


Q: How is a reaction described when the given conditions favor formation of products?


A:
spontaneous