Question

How can the rate of reaction be changed?

Answer 1

Hint: Rate is related to the speed. The rate of the reaction determines the speed of the reaction that is how fast or slow is the reaction.
- The branch of physical chemistry which determines the rate of the reaction is known as chemical kinetics.
- During the reaction concentration of the reactants decreases while the concentration of the products decreases.
- The change in the concentration of the reactants and products affect the rate of the reaction.

Complete step by step answer:
The different factors that affect the rate of the reaction are the concentration of the reactants, the pressure of gaseous reactants, size of the solid reactant, temperature, solvent, catalyst, etc.
1) Change in temperature:
As temperature increases, the activation energy of the molecules increases which leads to an increase in the collision between the reacting molecules, and hence the rate of reaction increases.

2) Change in pressure:
The change in pressure changes the concentration of the species. As pressure increases, the collision between the gas molecules also increases hence, the rate of the reaction also increases.

3) Concentration of the reactants:
As the concentration of the reactant increases, a collision between the reactant molecules also increases, and hence the rate of reaction also increases.

4) Size of the solid reactants:
As the surface area of the reactant increases the rate of the reaction increases. Therefore, the solid reactant in powdered form possesses more rate of reaction.

5) Solvent:
The rate of reaction also changes as the solvent is changed.

6) Catalyst:
The presence of the catalyst also affects the rate of the reaction. The presence of the catalyst increases the rate of the reaction.
All these factors affect the rate of reaction.

Note: The rate of the reaction is important to determine the speed of the reaction.
The unit of the rate of the reaction is the concentration per unit time. If the concentration is in molar and time is in seconds then the unit of the rate is molar per second.

The rate of the reaction is mathematically represented as follows:
${\text{rate = }}\dfrac{{{\text{change}}\,\,{\text{in}}\,\,{\text{concentration}}}}{{{\text{time}}}}$