Problem 32 - A Complete Resource Book in Chemistry for JEE Main

Question

The function of catalyst in chemical reaction is to (a) increase the product (b) decrease the product (c) accelerate the rate of reaction (d) increase the reactants

Step-by-Step Solution

Answer

(c) accelerate the rate of reaction

Step 1: Understand the Role of a Catalyst

A catalyst is a substance used to speed up a chemical reaction without itself being consumed. Its primary function is to lower the activation energy needed for the reaction to proceed, allowing it to occur more quickly.

Step 2: Evaluate the Options

Now that we know a catalyst speeds up a reaction, we need to relate this to the given options: (a) increase the product, (b) decrease the product, (c) accelerate the rate of reaction, and (d) increase the reactants. The correct attribute of a catalyst relates to (c) as it specifically accelerates the rate of reaction.

Step 3: Confirm the Correct Answer

Even though a catalyst can make a reaction occur faster, it does not alter the amount of products or reactants (hence does not affect options (a), (b), or (d)). Therefore, the role of a catalyst concurs only with option (c).

Key Concepts

Activation Energy

Activation energy is a crucial concept in understanding chemical reactions. It is the minimum energy required for a reaction to take place. In simpler terms, it acts as an energy barrier that needs to be overcome for reactants to transform into products.

Imagine trying to roll a ball over a hill. The hill represents the activation energy. You need enough energy to push the ball to the top so it can roll down the other side. In chemical reactions, this energy is needed to break bonds in the reactants so new ones can form in the products.

A catalyst works by lowering this hill—lowering the activation energy. This role of the catalyst allows the reaction to occur more easily and quickly without changing itself in the process. Remember:

• Activation energy is often represented as a peak in energy diagrams.
• Lowering this energy makes reactions feasible at lower temperatures.
• Catalysts do not alter the reaction's equilibrium.

Rate of Reaction

The rate of reaction pertains to how fast or slow a chemical reaction occurs. It's a significant factor in both natural processes and industrial applications.

The rate can depend on several factors like temperature, concentration of reactants, and the presence of a catalyst. Catalysts are particularly effective as they increase the rate of reaction by lowering the activation energy, making the conversion from reactants to products quicker.

Think of the rate of reaction like cooking on a stove. A higher flame leads to quicker cooking. Similarly, catalysts enable the reaction to proceed faster without increasing temperature. Some key points to remember include:

• A higher concentration of reactants usually leads to a faster reaction.
• Increasing the temperature typically speeds up reactions by providing more energy to molecules.
• The use of catalysts is pivotal in controlling reaction rates efficiently.

Chemical Reactions

Chemical reactions occur when substances (reactants) undergo a transformation to form new substances (products). These reactions involve breaking and forming chemical bonds, which calls for a certain amount of activation energy.

They are everywhere and essential to life, from digesting food to powering automobiles. Chemical reactions can be influenced by several factors including catalysts, pressure, and the physical state of reactants.

The role of a catalyst is central because it facilitates a more efficient pathway for reactions by decreasing the activation energy required. Some essential features of chemical reactions include:

• They usually involve a change in energy, either absorbing (endothermic) or releasing (exothermic) energy.
• A balanced chemical equation represents the reactants and products with involved proportions.
• Certain conditions like temperature and catalysts can significantly impact reaction pathways.