Activity coefficient

An activity coefficient measures how much a substance's behavior in a mixture deviates from its behavior in pure form. It helps us understand how interactions between different molecules affect their tendencies to react or dissolve compared to if they were alone. If the activity coefficient is 1, the substance behaves as it would on its own. If it's above or below 1, interactions with other components make it more or less active than expected. This concept is important in chemistry and engineering for predicting and controlling processes like reactions, dissolving, and material properties in mixtures.