Answer is increase the concentration of a reactant
The speed of a chemical reaction is affected by the factors such as concentration of the reactants, temperature, particle size, and the presence of a suitable catalyst. The rate of a reaction depends on the frequency and energy of collisions between particles. Increasing concentration of reactants, increases the rate of reaction because the collisions are more frequent among the particles of the reactants. Increasing temperature of the system also speeds up a reaction because there are more collisions and the collisions have higher energy.
