chemica kinetic 2016

Feasibility mean rxn hoga ya nahi

hoga. wo T,P,V,H,G per depend karta

hai.

Here we understand

speed of the reaction in everyday

life.

Fast reaction:-This rxn we already done in qualitative analysis practical. For detect of halogen. When we mix AgNO3 quickly white ppt form.

It take million of year for rusting metal.

Slow re

action

In this chapter we study in moderate rate of reaction.

Concentration = n/V

That part is very small so at that when find very small range. We use the method

limit.

Suppose we take glass of

water

But we have two type of

sugar with us.

Catalyst

The law of mass action is a purely

theoretical concept.

Unit of rate constant of

1st order reaction are S-1.

Remember this order is based

on experimental only.

Order base on experimental not based on

reactant concentration.

Molecularity of Reaction

Molecularity based on

theoretical only.

Such type of reaction take

place through a sequence of two

or more consecutive

steps.

Slowest step shows the

overall rate of reaction is called RDS.

Intermediate reaction is formed

in 1 step and consumed in 2nd

step.

Some additional species other then reactant or product is produced in the mechanism called intermediate.

Integrate rate laws

The equation which are obtained by integrating the differential rate laws and which give a direct

relationship between the concentrations of the reactants and times.

Shows the relationship between time and

reactant concentration

A Product

R = -d[A]/dt = k[A]t + 0 Y = m x + c

[A]t = [A]0 e-kt

Y= [A]t X= t

Zero order reaction defined as Reaction whose rate is independent of the reactant concentration and

remains constant throughout the course of the reaction.

x is the amount

consumed in time t.

Rate = -d[A]/dt = k

[A]t

Example of zero order reactions• Decompostion- on Pt surface2NH3(g)

2N2O(g)

PH3 on hot tungston at high pressure unreacted fully.

Pt surrounded by NH3 but only NH3 react with surface of Pt. In this reaction we cant

say rate is depend upon reactant concentration.

Such reaction that have higher order true rate law but are found to behave as first order are called….

Order is an experimentally

determined value.

Every reaction can have only one

particular order.

It happened in those reaction

which contain one solvent.

For finding reaction order we take one

concentration large excess.

Order is high but behaves as 1st order

Apparent order also called fake

order.

This method applicable-

a) Only one reactantA B

b) The order should be integer.

This method applicable-

a) Multiple reactantA + B + C Productb) The order should

be integer.

Svante Arrhenius

Svante August Arrhenius

19 February 1859Wik Castle, Sweden

The reaction rate almost double for every 10

degree rice in temperature.

In this reaction we are using catalyst

Iodine.

2H2O 2H2O + O2

In this reaction we are using catalyst Iodine.

2H2O 2H2O + O2

2KClO3 → 2KCl + 3O2 (Mno2)2H2O2 → 2H2O + O2 (I2)

Catalyst lower the energy barrier.

Svante August Arrhenius

19 February 1859Wik Castle, Sweden

T2 > T1

K2 > K1

Collision Theory And Activation Energy

Effective CollisionRequire Necessary Ea Energy.

GAS PHASE RXN COLLISION IS VERY HIGH STUDY BY

KINETIC MOL THEORY OF GAS

if collision is successful then product formation time is 10-9.

K.E ≥ Ea

THE MINIMUM K.E REQUIRE FOR A MOLECULEAR COLLISION TO LEAD TO REACTION.

3.Orientation of reactant molecule

If orientation is not correct they repelled each other.

Affective collision

when element are arranged in

proper orientation.

Energy of collision comes

from K.E. of colliding

particles.

The minimum energy that molecules need to have in order for a reaction to take place is called the threshold energy.The activation energy is what you need to supply to the

molecules that don't have enough kinetic energy to reach the threshold energy.

All Atom Weakly Link Together.

Potential energy barrier

The fraction of collision that passes the energy f = e –Ea/RT

Collision rate = Z [AC][B]Rate of reaction = P.f x collision rateRate of reaction = P.f.Z[AC][B]Rate of reaction = k [AC][B] where K= P.f.Z

But, f = e –Ea/RT K = P.Z. e –Ea/Rt K = Ae-Ea/RT A= P.Z called frequency factor/ pre-exponent factor.

P is a steric factor that accounts for the need for the molecules to be in the proper orientation.