Factors Affecting Rate Of Reaction

In a chemical reaction, the products are formed from the reaction at a certain speed which is referred to as the rate of reaction. The rate of reaction gives important insights into the time frame that is required for the reaction to be completed. However, there are certain factors affecting the rate of reaction. Let us take an example of the combustion of cellulose in fire, the rate of reaction is high, and the reaction is completed in less than a second.

Table of Contents:

What is the Rate Of Reaction?
Factors Affecting the Rate of Reaction
Nature of the Reaction
Concentration of Reactants
Pressure
Temperature
Solvent
Electromagnetic radiation and Light Intensity
Presence of Catalyst
The surface area of the reactants
Practice Problems On Factors Affecting Rate Of Reaction

What is The Rate Of Reaction?

The rate of reaction is referred to the reaction speed at which the reactants transform into the products. In chemical reactions, the rate of reaction varies depending on the reactants and other factors. However, some chemical reactions are instantaneous, while other reactions are slow to reach the condition of equilibrium.

For example, the rate of reaction in the combustion of wood is high as the process is fast, and the rate of reaction in rusting of iron is low, as the process is slow and takes a long time.

Factors Affecting the Rate of Reaction

There are various factors that affect the rate of reaction, such as pressure, temperature, nature of the reaction, etc. Some of the factors are listed below.

Nature of the Reaction

The rate of reaction mainly depends on the nature of the reaction. Some reactions are naturally faster, while some are very slow. Factors such as the physical state number of reactants also highly influence the rate of reaction. Generally, the rate of reaction in liquids is slower compared to gases and the rate of reaction in solids is slower compared to liquids. Thus, the rate of reaction is faster when the size of the reactant is small.

Concentration of Reactants

When the concentration of the reactants increases, the rate of reaction also increases based on the collision theory. Based on the mass action law, the rate of a chemical reaction is directly proportional to the concentration of the reactants. Thus, the rate of chemical reaction increases with the increase in the concentration of reactants. Time is also a significant factor in changing the concentration of reactants and products.

Pressure

The concentration of gases is increased by the pressure, which results in an increase in the rate of reaction. It increases in the direction of gaseous molecules and vice versa. Thus, the concentration and pressure of the reaction are interlinked and affect the rate of reaction.

Temperature

Based on the collision theory, the reaction that takes place at a high temperature produces higher energy compared to the reaction at a lower temperature because the colliding particles reach the required energy only at a high temperature for the collision process.

Solvent

The rate of reaction is additionally influenced by the type of solvent, solvent properties and ionic strength.

Electromagnetic radiation and Light Intensity

Electromagnetic radiation is defined as an energy type that expands the rate of reaction in the chemical process by producing high energy to the reactant particles. The particles of the reaction absorb high energy with the increase in light intensity. Thus, the increase in light intensity increases the rate of reaction.

Presence of Catalyst

A catalyst is referred to as a material that creates an impact on a chemical reaction by increasing the rate of reaction without disturbing the reaction. The catalyst increases the rate of reaction in the forward and reverse reactions.

The Surface Area of the Reactants

The reactant's surface area has an impact on the reaction rate. If the molecule size is small, the surface area will be greater. This great surface area helps in speeding up the heterogeneous chemical reaction. Thus, the greater the surface area, the higher the rate of reaction.

Practice Problems On Factors Affecting Rate Of Reaction

Q1. Which of the following is correct about the rate of reaction?

a. Speed of the reaction
b. Nature of the reaction
c. The temperature of the reaction
d. None of the above

Ans: a. Speed of the reaction

The rate of reaction is defined as the speed of the reaction at which the reactants are changed to the products.

Q2. Which of the following doesn’t take part in the reaction?

a. Products
b. Reactants
c. Catalyst
d. None of the above

Ans: c. Catalyst

A catalyst is a material that creates an impact on a chemical reaction by increasing the rate of reaction without disturbing the reaction.

Q3. The rate of reaction in the combustion of wood is _________ the rusting of iron.

a. Higher than
b. Lower than
c. Equal to
d. None of the above

Ans: a. Higher than

The rate of reaction in the combustion of wood is high as the process is fast, and the rate of reaction in rusting of iron is low, as the process is slow and takes a long time.

Frequently Asked Questions

Q1. What is meant by reactants and products?
Answer: Reactants refer to substances or materials that undergo a chemical reaction. Products refer to the end products or new products as the result of the chemical reaction.

Q2. What is Activation energy?
Answer: Activation energy is defined as the minimum amount of energy required to activate the atoms or molecules to initiate a chemical change. Activation energy helps to overcome the energy barrier.

Q3. What is a first-order reaction?
Answer: A first-order reaction is a chemical reaction in which the reaction rate is directly subjected to the concentration of one reactant.