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
5. 5
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”
7. 7
TYPES OF ORDER REACTION
1. First order reaction
2.Second order reaction
3.zero order reaction
8. 8
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:
10. 10
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
11. 11
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