Increasing the surface area of a reactant in a chemical reaction generally leads to an increase in the reaction rate. This is because a larger surface area allows for more particles of the reactant to be exposed and available for collisions with other reactant particles. As a result, there is a higher probability of successful collisions between reactant particles, leading to a faster formation of products. This effect is particularly noticeable in heterogeneous reactions, where reactants are in different phases e.g., solid and gas .