Catalysts

Published on May 30, 2016

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Suppose you are doing a reaction in your chemical lab but it takes three to four hours for that reaction to complete. So you are standing idly while your friend is already out finished with his reaction. How did he make that possible? Well, there are several ways in which he could have accomplished it, like increasing the temperature or the concentration of the reactants or even by using something known as a catalyst. A catalyst is a substance which is used to increase the rate of a chemical reaction without the consumption of the catalyst itself.

Activation energy

Whenever you are conducting a reaction and the reactants undergo a change to form the products, there is an energy change associated with the complete reaction as well. It is a well-known concept in chemistry that products usually have lower energy than the reactants. This increase in energy of the reactants is the cause of their instability and they readily react to form the products which have lower energy and, thus, more stability. However, in order to go from reactants to products, the reactants have to go through a phase which is called the transition phase. In this transition phase, the old bonds and new bonds are thought to co-exist simultaneously such that neither it actually existing but their effects can be felt. This transition state is more unstable than the state in which reactants were initially and so it is associated with a higher energy. If a reactant has to undergo a change to form products, it must be have enough energy to overcome this barrier.

How do catalysts work?

There is a steep energy hill which the reactants have to climb first and then slide along the other side to become products. This energy comes from a source which might be internal or external. There are certain reactions which lead to an evolution of energy which can be utilized by the reactants to undergo the change. Energy can also be supplied externally by increasing the temperature of the system and allowing the particles to gain enough kinetic energy to cause the reaction. But catalysts work in a different way than fulfilling the existing energy requirements. They provide an alternative path for the chemical reactions to take place so that the new energy requirements are lower than the previous one. Thus, while they do not help the reacting molecules in obtaining enough energy to hop over the hill, they do decrease the height of the hill so that there is less to climb.

Applications of catalysts

Catalysts are used in various industries, and it is estimated that all the chemical industries make use of catalysts in one form or the other. Catalysts are used in petroleum refining as well as in hydrogenation of fats. Catalysts are important because they make every reaction go faster and time is a vital factor in any industry. They also lower the energy requirements and so it becomes easier to conduct reactions which normally would have higher energy considerations. Catalysts have become indispensable in all the branches of chemistry.

 

 

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