Free Study Material

NCERT Solutions

NCERT Books

Revision Notes

Practice Problems

This is one of our many quizzes on Catalysts. Click on this to access more such competitive quizzes on General Chemistry.

Catalysts Quiz 2

chemistry

Identify which of the following reactions comes under the category of homogeneous and heterogeneous catalytic reactions. 1. $2S{{O}_{2}}(g)+{{O}_{2}}(g)\xrightarrow{Pt(s)}2S{{O}_{3}}(g)$ 2. $C{{H}_{3}}C{{H}_{2}}OH(l)\xrightarrow{Ni(s)}C{{H}_{3}}CHO(l)+{{H}_{2}}(g)$ 3. $2S{{O}_{2}}(g)+{{O}_{2}}(g)\xrightarrow{NO(g)}2S{{O}_{3}}(g)$ 4. ${{N}_{2}}(g)+3{{H}_{2}}(g)\xrightarrow{Fe/Mo}2N{{H}_{3}}(g)$

 When all [reactants, products and catalyst] are in the same phase i.e. either solid, liquid or gas, then, the reaction is called as homogeneous catalytic reaction and when all [reactants, products and catalyst] are in the different phase i.e. either solid, liquid or gas, then, the reaction is called as heterogeneous catalytic reaction.

When the catalyst is in the same phase as the reactants and the products, then the reactions are called homogeneous catalytic reactions. On the other hand, when the catalyst is in a different phase than the reactants and the products, then the reactions are called heterogeneous catalytic reactions. So, $2S{{O}_{2}}(g)+{{O}_{2}}(g)\xrightarrow{NO(g)}2S{{O}_{3}}(g)$is a homogeneous catalytic reaction. and $2S{{O}_{2}}(g)+{{O}_{2}}(g)\xrightarrow{Pt(s)}2S{{O}_{3}}(g)\\ $, $\\ C{{H}_{3}}C{{H}_{2}}OH(l)\xrightarrow{Ni(s)}C{{H}_{3}}CHO(l)+{{H}_{2}}(g)$ and $\\ {{N}_{2}}(g)+3{{H}_{2}}(g)\xrightarrow{Fe/Mo}2N{{H}_{3}}(g)$ are heterogeneous catalytic reaction

Match the enzyme catalysts in column A with their enzymatic reactions in Column B.<img src="https://cmds-vedantu.s3.ap-southeast-1.amazonaws.com/prod/question-sets/2ff3a9a3-383c-444c-b105-86c032139a7a5127979343217658535.png"/>

 Zymase is an enzyme used in the breakdown of glucose, diastase is used in catalysis of starch and urease is used in catalysis of urea to ammonia.

What would be the catalysts in the following given reactions:-<img src="https://cmds-vedantu.s3.ap-southeast-1.amazonaws.com/prod/question-sets/50a75858-774c-453c-bc53-b1594bc4d2494540225137576503639.png"/>

  The decomposition reaction of ozone takes place in the presence of Cl; the formation Sulphur trioxide occurs in the presence of Pt and the formation of formaldehyde occurs in the presence of Cu.

Match the column A with column B<img src="https://cmds-vedantu.s3.ap-southeast-1.amazonaws.com/prod/question-sets/d5de51b6-a078-4dab-b68e-3095f05e8bb5461925922047829004.png"/>

 The reactions in which the catalyst is in the different phase than the reactants and the products, then the reactions are called heterogeneous catalytic reactions and Mo acts as a promoter in the formation of ammonia. In the presence of positive catalysts, the activation energy decreases whereas in the presence of negative catalysts, it increases.

 There are catalytic reactions which depend upon the pore structure of the catalyst and the size of the reactant and the products known as the shape selective catalysis and zeolites are considered as good shape selective catalysts. Why is it so?

 Zeolites are aluminosilicates minerals which are microporous. They are commercially used as catalysts and adsorbents.

 Zeolites are the shape selective catalysts and in this the catalytic reactions depend upon the pore structure of the catalyst and the size of the reactant and the products. This has a honeycomb like structure which makes it a good shape for selective catalysts and  the pore size in zeolites varies between 260pm to 740 pm.