Catalyst

Definition

A catalyst is a substance that increases the rate of a chemical reaction without being consumed or altered itself. Catalysts work by providing an alternative pathway for the reaction, which lowers the activation energy required and allows the reaction to proceed more quickly.

5 Must Know Facts For Your Next Test

1. Catalysts can be used to increase the rate of a reaction without being consumed or altered themselves, making them reusable.
2. Catalysts work by providing an alternative reaction pathway with a lower activation energy, allowing the reaction to proceed more quickly.
3. Catalysts can be either organic (e.g., enzymes) or inorganic (e.g., metal catalysts used in industrial processes).
4. Enzymes are a type of biological catalyst that are essential for life, as they speed up the many chemical reactions that occur in living organisms.
5. The presence of a catalyst does not affect the overall thermodynamics of a reaction, but rather the kinetics by lowering the activation energy barrier.

Review Questions

• Explain how a catalyst affects the energy diagram of a chemical reaction.
  • A catalyst affects the energy diagram of a chemical reaction by lowering the activation energy required for the reaction to occur. Normally, reactants must overcome a significant energy barrier to reach the transition state and form products. However, the presence of a catalyst provides an alternative pathway with a lower activation energy, making it easier for the reaction to proceed. This is depicted on the energy diagram as a reduction in the height of the energy barrier between reactants and products, with the catalyst stabilizing the transition state and facilitating the reaction.
• Describe the role of catalysts in enzyme-catalyzed reactions.
  • Enzymes are biological catalysts that play a crucial role in speeding up the many chemical reactions that occur in living organisms. Enzymes work by binding to the reactants (substrates) and providing an alternative reaction pathway with a lower activation energy. This allows the reaction to proceed much faster than it would without the enzyme present. Enzymes are highly specific, recognizing and binding to particular substrates, and they are not consumed or altered during the reaction. This makes enzymes reusable and efficient at facilitating the numerous metabolic processes necessary for life.
• Analyze how the use of catalysts in industrial processes can improve the efficiency and sustainability of chemical manufacturing.
  • The use of catalysts in industrial chemical processes can significantly improve the efficiency and sustainability of manufacturing. Catalysts allow reactions to occur at lower temperatures and pressures, reducing the energy input required. This leads to lower operating costs and a smaller environmental footprint. Additionally, catalysts can increase the selectivity of a reaction, producing the desired product more efficiently and generating less waste. Many industrial catalysts can also be recycled, further enhancing the sustainability of the process. By lowering the activation energy and facilitating reactions, catalysts play a vital role in making chemical manufacturing more efficient, cost-effective, and environmentally friendly.

Related terms

Activation Energy: The minimum energy required to start a chemical reaction. Catalysts lower the activation energy, making the reaction more favorable.

Transition State: The unstable, high-energy intermediate stage that a reaction must pass through to go from reactants to products. Catalysts stabilize the transition state, facilitating the reaction.

Enzyme: A type of biological catalyst that speeds up chemical reactions in living organisms by lowering the activation energy.