Question

Explain the effect of temperature on the rate of reaction.

Short answer

In conclusion, temperature plays a significant role in the rate of a chemical reaction. As temperature increases, the particles have more kinetic energy, leading to more frequent collisions and a higher probability of successful collisions that exceed the activation energy needed for the reaction to occur. Therefore, an increase in temperature generally results in an increased rate of reaction. This relationship can be represented mathematically using the Arrhenius equation. Overall, understanding the effect of temperature on reaction rates is a crucial aspect of chemistry and helps in controlling the speed of various chemical processes.

Step-by-step solution

Introduction

The rate of a reaction is the speed at which the reactants are transformed into products. One of the factors that affect the rate of a reaction is temperature. In this explanation, it will be demonstrated how temperature influences the rate of reaction and the underlying concepts related to this phenomenon.

Collision Theory

The basis for understanding the effect of temperature on the rate of reaction lies in the Collision Theory. This theory states that in order for a reaction to occur, the reacting particles must collide with a specific minimum energy called the activation energy (Ea). An increase in temperature results in an increase in the average kinetic energy of the particles, leading to a higher probability of successful collisions.

Activation Energy

Activation energy (Ea) is the minimum amount of energy that must be supplied to the reactants to form a product. At a lower temperature, fewer particles possess the required energy to surpass the activation energy barrier. As the temperature increases, the fraction of particles with energy higher than Ea also increases, allowing more successful collisions and hence an increased rate of reaction.

Effect of Temperature

When the temperature increases, the particles in the reaction move faster due to their increased kinetic energy. This results in more frequent collisions between the particles, and since, as mentioned earlier, there is also a higher fraction of particles with energy higher than the activation energy, more of these collisions result in a reaction. Consequently, the rate of reaction increases with the increase in temperature.

Arrhenius Equation

This relationship between temperature and the rate of reaction can be described mathematically using the Arrhenius equation: k = Ae^{\frac{-Ea}{RT}} where: - k is the rate constant of the reaction, - A is the pre-exponential factor (collision frequency), - Ea is the activation energy, - R is the universal gas constant, and - T is the temperature in Kelvin. This equation shows that as temperature (T) increases, the value of the exponential term will increase, resulting in an increased rate constant (k) and, consequently, a higher rate of reaction. In summary, an increase in temperature has two primary effects on the rate of reaction: it increases both the frequency of collisions between particles and the probability of successful collisions that surpass the activation energy barrier. As a result, the rate of reaction increases with increasing temperature.