Catalysts
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“Catalysts” refer to substances that increase the rate of a chemical change without undergoing any permanent changes themselves.
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They operate by providing an alternate reaction path that has a lower activation energy, essentially lessening the energy required to kick start a reaction.
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Catalysts are divided into two main categories; heterogeneous and homogeneous catalysts. Heterogeneous catalysts are in a different state to the reactants, whilst homogeneous catalysts exist in the same state as the reactants.
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Enzymes, nature’s catalysts, perform pivotal roles in numerous biochemical reactions. They have a highly specific action, meaning they only catalyse certain reactions due to their unique active sites.
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Catalysts aid in increasing the efficiency of industrial processes by accelerating the rate of reaction, often enabling certain reactions to occur at lower temperatures than would otherwise be necessary.
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The factors that can affect the efficacy of a catalyst include its particle size and surface area. Smaller particles and larger surface areas offer more sites for reactant interaction, explicating more of the catalyst’s potential.
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Increasing the concentration of the catalyst in the reaction mixture can also raise the rate of reaction by providing more active sites.
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Catalysts might seem ‘used up’ at the end of a reaction, but they are not consumed; it is simply that they may be chemically covered by the products of reaction. By heating or scraping, the catalyst can be regenerated and its effects restored.
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Catalysts, while valuable, can be related to negative environmental implications. For example, certain catalytic chemical processes result in harmful byproducts or enable reactions that produce damaging pollutants.
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Real-world applications of catalysts cover a vast range, from catalytic converters in vehicles that reduce harmful emissions to processes in the chemical industry like the Haber process (making ammonia) or the Contact process (making sulphuric acid) where catalysts play a crucial role in improving the rates and viability of these reactions.