Chemistry Project file on Catalysis. Contains brief info abt catalysis Edited by Shashank

1. TOPIC-
SUBMITTED BY – abhIshek sharma
CLASS – XII sCIENCE
ROLL NO –
SUBMITTED TO - MRS. VEENA TYAGI

2. I am thankful to those people who helped me to
prepare this report on chemistry.
I am thankful to Mrs. Archana Goswami our
chemistry teacher for giving their valuable
support because without their help, I would not be
able to complete my project report.

3. Catalysis is a substance which can change
the speed of a chemical reaction without
itself undergoing any change in mass and
chemical composition at the end if the
reaction and the phenomenon are known as
‘’Catalysis’’.
Catalysis of two types;
➢Positive catalysis
➢Negative catalysis

4. A catalyst in which the catalyst increases
the rate of reaction is called ‘’positive
catalysis’’.
Platonized asbestos is used in the contact
process for the manufacture of sulphuric acid
is an example of positive catalyst.
A catalyst that is employed to decrease the
rate of reaction is called as ‘’negative
catalysis’’.
Phosphoric acid retards the decomposition of
hydrogen peroxide.

5. ➢Homogenous Catalysis
➢Heterogeneous Catalyst
Homogeneous
Catalyst
A catalytic process, in which catalyst and the
reactants are in the same phase, is known as
“Homogeneous catalysis”.
Example: 2so2(g) s2+2o2
The reactant and the catalysis all are in same face. It
can be explained by two stage mechanism involving
the formation of NO (nitric acid) gas as an
intermediate compound.
2NO + O2 2NO2

6. SO2 + NO2 SO3 + NO
It is based on “Intermediate Theory”. In
this,catalyst forms bonds with one of the
reactant and thus form intermediate with
lower form intermediate with lower value of
activation energy providing alternate part of
reaction mechanism. After that it combines
with other reactant forming the product and
the catalyst is angulated.
Many organic reactions are catalyzed by
hydroxyl ion were both the catalyst and
reaction are present in liquid phase.
Invention of cane sugar and hydrolysis of
esters are catalyzed.
Condensation in alcohol or autorotation
of sugarcane is catalyzed hydroxyl.

7. Heterogeneous
Catalysis
A catalytic process, in which catalyst and the
reactants are not in the same phase, is known
as “Heterogeneous catalysis”.
N2 (g) +2H2 (g) 2NH3 (g)
It is based on “Adsorption theory”. In this,
reactants are generally gases and catalyst is
solid. Now reactants are physiosorbed and
chemisorbed on the surface of catalyst
increase the rate of reaction. Hence, product
forms have no affinity on the surface of
catalyst and thus have the area of catalyst
free for next adsorption.

8. Enzymes are bio-catalyst band phenomenon
is known as
“biochemical catalyst”
Enzymes are nitrogenous organic compound
which is produced by living plants and
animals.
They are actually protein molecules of high
molecular mass.

9. Mechanism of enzyme catalysis
There are a number of cavities present
on the surface of molecules of
enzymes.
These cavities are of characteristics
shapes posses’ active groups. They are
actually active center on the surface of
enzyme particles.

10. Aim: To determine the principle of
autocatalysis using bromophenol as indicator.
Apparatus: 100ml beaker and 100ml
graduate cylinder.
Chemicals Required:
4ml potassium chlorate, 12.5 sodium sulphate
and 5mg bromophenol.
Principle:
This is a redox reaction.
Clo3
-
+3H2SO4
Cl -
+3SO4
2-
+3H+
The reaction proceeds only in acidic
environment.

11. Adding sulphuric acid further catalyzed the
reaction.
This is the Auto catalyses effect.
Bromophenol blue indicator is yellow in highly acidic
solution. The solution has ph between 6.4 and 7 due
to the suffering effects of the bisulphate ions. As
autocatalysis precedes ph decreases and the blue color
of the indicator changes to yellow. The extra energy
which the two molecules must possess in order to react
in termed as activation energy.
In the absence of catalyst, activation energy in the
reaction takes place between small fractions of
molecules with high energy and therefore the reaction
is quit slowly. Whereas in the presence of the catalyst
the activation of the reaction is comparatively
lowered and even react with lower energy. Hence,
more of the molecules participate in the reaction
which takes place in the presence of catalyst. Many
catalytic processes can be explained on the bases of

12. this theory {intermediate compound formation
theory}
O2+2NO 2NO2
NO2 +SO2 SO3+NO
Procedure:
✓ Place 50ml of water in beaker.
✓Subsequently, dissolve 4 gm of KCl, 12.5gm
sodium sulphate and 5mg of bromophenol.
✓Prepare a 3ml solution of sulphuric acid and 5ml
of sulphuric acid to 18ml of distilled water.
✓In second beaker 4ml to 3ml of sulphuric acid
and 5ml of water and stirring.
✓Slowly with constant stirring add diluted acid
from second beaker to the blue solution of the
first.
✓Stir until whole solid dissolve.
Result:
The yellow blue interface moves slowly down the
graduated cylinder indicating the autocatalytic effect.

13. Characteristics of Catalyses
Reaction
The catalyses substance i.e. catalyst does not change
mass of the composition as the result of the chemical
reaction it may, however undergoes a physical
change.
Example: during the decomposition of potassium
chlorate, amegadioxide found to have changed from a
course power to find one at the end of the reaction. A
very small quantity of the catalyses is needed to
accelerate a chemical reaction.

14. Autocatalysis
Some reactions are slower to start with but after some
time they are quit rapid and this is due to
information of one of the product (during reaction)
which acts as catalyst and this phenomenon is known
as “Autocatalysis”.
Reaction between nitric acid and copper is slow to
start in beginning but gains speed gradually and is
quit brisk after sometimes, in the case nitrous acid is
one of the products of reaction which accelerates the
reaction.
The titration of potassium permanganate against
oxalic acid and sulphuric acid.
Induced Catalysis
The phenomenon in which one reaction induces the
other reaction is called “INDUCED CATALYSIS”.

15. It is the combination of the “OLD
ADSORPTION THEORY”. According to this
theory, there are free valances in the surface of
the solid catalysts.
Mechanism of catalyses involves following
steps:
Diffusion of reactant molecules towards the
surface of catalyst.
Adsorption of the reactant molecules on the
surface if catalyst by forming loose bonds with
the catalyst due to presence of frees valences.
Occurrence of a chemical reaction between the
reactants and the catalyst forming an
intermediate.
Desorption of the product molecule from the
surface due to lack of its affinity for the catalyst
surface there by making the activity of catalyst.

16. NCERT BOOK
PRADEEP REFERENCE BOOK
INTERNET
WIKIPEDIA

17. This is to certify that ABHISHEK SHARMA of
class XII Science of Nav-Jiwan Public School ,
Faridabad has completed her project under her
supervision.
She has taken proper care and shown whole
sincerity in completion of this project is up to
my expectation and as per guidance issued by
CBSE.