Order of reaction

chemistry

1. 1
QURATULAIN MUGHAL
BATCH IV
DOCTOR OF PHYSICAL THERAPY
ISRA UNIVERSITY

2. 2
CHEMICAL KINEMATICS
DEFINITION:
“the branch of physical chemistry which
deals with the rate of chemical reactions
and the mechanism through which they
occur is called chemical kinematics”

3. 3
RATE OF REACTION
•DEFINITION:
“the decrease in concentration of reactant or
increase in concentration of the products
of the reaction at a given moment of time
is called rate of reaction”
FORMULA:
dx/dt=K

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CONTI…..
•Where,
dx=change in concentration
dt=time taken for change
K= reaction rate constant

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ORDER OF REACTION
•DEFINITION:
“the number of reacting molecules whose
concentration alters as a result of chemical
change is called the order of reaction”
OR
“the sum of exponents in the rate expression of a
reaction is the order of reaction”
OR
“the power to which concentration of reactant is to
be raised to get the rate of reaction”

6. 6
CONTIN……
•EXAMPLES:
mA+rB product
rate = K[A] ͫ [B] ͫ
The oder of reaction= (m+r)

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TYPES OF ORDER REACTION
1. First order reaction
2.Second order reaction
3.zero order reaction

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FIRST ORDER REACTION
•If a reaction rate depends on a single
reactant and the value of the exponent is
one, then the reaction is said to be first
order.
•r = k [A]
•FORMULA:

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FIRST ORDER REACTION

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SECOND-ORDER REACTION
•the rate of reaction is directly proportional
to the square of the concentration of one
of the reactants.
•r = k [A]
2

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ZERO-ORDER REACTION
•For a zero-order reaction, the rate of
reaction is a constant. When the limiting
reactant is completely consumed, the
reaction abrupt stops.
•r = k

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