Hi chemistry lover guys.
In this article im gonna talk about catalysts.
So,
what is catalyst?
Catalysts are some chemical substance that can affect the rate of a chemical reaction without being changed in quantity or quality.
So the most important fact about catalysts is it remain unchanged in its chemical properties but affect the rate of reaction in which it participate.
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Classification.
Catalysts can be classified based on there work and there physical state.
Classification based on work in a chemical reaction.
1. Positive catalyst.
2.Negative catalyst.
Positive catalyst
Positive catalysts are generally increase the rate of reaction. These are used to increase the rate of reaction so how they increase the rate of reaction?
Positive catalyst mainly lowers the activation energy that is they make another shorter path to make reactant particles to pass the activation energy hill easily as a result a more number of particle can participate in the chemical reaction and the rate of reaction increased.
Venadium pentaoxide is an example of positive catalyst it increases the rate of reactiom of sulphur dioxide to sulphur trioxide preparation in Heber boss process .
Negative catalyst
Negative catalysts are also known as inhibitor these make the reaction rate slower. They actually increases the activation energy of a chemical reaction so the activation energy hill become more higher is difficult to pass for the reactant molecules as a result the rate of reaction decreases.
The great example of of a negative catalyst is H3PO4 which works in the decomposition of hydrogen peroxide. That is phosphoric acid decreases the rate of decomposition of hydrogen peroxide.
While classifying catalyst according to their physical state they are of two types.
1. Homogenous catalyst.
2. Heterogeneous catalyst.
Homogenous catalyst
A homogenous catalyst are normally catalyst that are in same physical state with the reagents in a particular chemical reaction. In our body a lot of chemical reactions are occured and enzymes act as catalysts.
These are same phage with the reactants so they can be a good example of homogenous reactants.
Heterogeneous catalyst
Heterogeneous catalysts are catalyst that are in different phage with the reactant molecules in a particular chemical reaction
Let us consider a chemical reaction of hydrogenation of alkene, in this chemical reaction reactant alkene and hydrogen all are in gaseous phage here Ni/Pt can be act as a catalyst. Now think about the physical state of Ni, it is a metal its physical state is solid.
So here Ni is a heterogeneous catalyst.
If any question ask in the comment section.
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