Chemical Reaction Engineering is the
study of the rate at which reaction takes place and
effect the parameters such as Temperature, Pressure
and Concentration of reactants.
Chemical reaction engineering gives
the information about the rate of the mechanism,
speed of reaction and type of reaction which can
be used in designing of reactions in bioreactor.
FUNDAMENTAL CONCEPTS OF
Reaction rate or Rate of reaction
Rate law or Rate of reaction or Kinetic
RATE OF REACTION
It is defined as change in
molar concentration of species per unit time
or rate at which change in concentration of
reactants decreases per unit time or increase
in concentration of products per unit time.
Rate = -change in conc. of reactants
-ve sign indicates decrease in concentration of reactants.
Rate = change in conc. of products
+ve sign indicates increase in concentration of products.
Rate = change in conc.
= mol ∕ lt.sec
RELATION BETWEEN THE CONCENTRATION OF
REACTANTS AND PRODUCTS OR RATE OF REACTION
REPRESENTATION OF GENERAL EQUATION
Consider xA+yB mC+nD
The relation between rates
measured with respect to A,B C and D
-1 dA=-1 dB=1/m . dC=1/n . dD
x dt dt dt
RATE LAW OR RATE EQUATION OR KINETIC LAW
The equation which relates the rate of
reaction and the concentration of reactants in a
reaction is called rate law or rate equation .
Consider an equation:
Rate α [A]x [B]y
This equation is called rate equation where x,y
are powers of the concentration of reactants.
‘k’ is rate constant
Rate constant of a chemical reaction is a measure of
rate of reaction, when all reactants are unit conc.
Rate constant = Rate of reaction
Rate= Rate concentration
Rate constant depends on temperature
Rate constant α temperature
Rate constant (k) = Rate of reaction
k = mol.lit-1.sec-1
These two equations are called general nth order
The rate constant ‘k’ for a reaction is simply
denotes how fast the reaction occurs if all the reactants
are brought about unit concentration.