Which term describes the speed at which reactants turn into products?

The term that describes the speed at which reactants turn into products is the reaction rate. This concept refers to the change in concentration of reactants or products in a chemical reaction over a specific period of time. It is typically expressed in terms of molarity per unit time (e.g., M/s). Understanding the reaction rate is crucial for predicting how fast a reaction will occur, which can depend on various factors such as temperature, concentration, presence of catalysts, and the nature of the reactants themselves.

In contrast, concentration change refers to the actual change in the amount of reactants or products over time, but does not encapsulate the notion of speed. The equilibrium constant relates to the ratio of concentrations of products to reactants at equilibrium, and does not describe the dynamics of how quickly a reaction occurs. Catalytic rate refers specifically to the rate of reaction in the presence of a catalyst, which is a specific scenario rather than the general concept of reaction rate. Thus, reaction rate is the most accurate term for describing the speed of a chemical reaction.