Collision Theory Chemical reactions occur when particles of reactant collide with enough energy to react. This minimum energy is called the Activation Energy. Smaller object react faster because there is a greater surface are to volume area ratio, therefore there are more collisions, and more frequently. The rate of reaction decreases as the concentration of reactant becomes less, and more products are made. As the temperature increases, the rate of reaction increases as the particles have more kinetic energy, therefore they collide more frequently. More particles achieve activation energy. Temperature Increasing the temperature of a reaction SPEEDS it up (INCREASES the rate of reaction) The particles have more kinetic energy so they move about more and collisions occur more frequently. As there are more collisions, there are more successful collisions so the rate of reaction increases. Concentration Increasing the concentration of reactant liquids in a reaction also increase the rate of reaction. A high concentration means more particles per cm3 so there are more collisions per second which means there are more successful collisions so the reaction speeds up. Surface Area Increasing the surface area of a reactant solid increases the rate of reactions. A powdered substance always has a larger surface area than a block substance weighing the same amount.
Collision Theory Chemical reactions occur when particles of reactant collide with enough energy to react. This minimum energy is called the Activation Energy. Smaller object react faster because there is a greater surface are to volume area ratio, therefore there are more collisions, and more frequently. The rate of reaction decreases as the concentration of reactant becomes less, and more products are made. As the temperature increases, the rate of reaction increases as the particles have more kinetic energy, therefore they collide more frequently. More particles achieve activation energy. Temperature Increasing the temperature of a reaction SPEEDS it up (INCREASES the rate of reaction) The particles have more kinetic energy so they move about more and collisions occur more frequently. As there are more collisions, there are more successful collisions so the rate of reaction increases. Concentration Increasing the concentration of reactant liquids in a reaction also increase the rate of reaction. A high concentration means more particles per cm3 so there are more collisions per second which means there are more successful collisions so the reaction speeds up. Surface Area Increasing the surface area of a reactant solid increases the rate of reactions. A powdered substance always has a larger surface area than a block substance weighing the same amount.