CBSE Class 12 Chemistry Chemical Kinetics Notes Set D

CBSE Class 12 Chemistry notes and questions for Chemical Kinetics Part B. Learning the important concepts is very important for every student to get better marks in examinations. The concepts should be clear which will help in faster learning. The attached concepts made as per NCERT and CBSE pattern will help the student to understand the chapter and score better marks in the examinations. 

CHEMICAL KINETICS

CONCEPT

Thermodynamics helps us to predict the feasibility of chemical reaction by using ΔG as parameter but it cannot tell everything about the rate of reaction. Rate of chemical reaction is studied in another branch of chemistry called Chemical Kinetics.

Chemical kinetics- The branch of physical chemistry which deals with the study of rate of reaction and their mechanism is called chemical kinetics.

Rate of chemical reaction- The change in concentration of any reactant or product per unit time is called rate of reaction.

TYPES OF RATE OF REACTION-

1. Average rate of reaction- The rate of reaction measured over the long time interval is called average rate of reaction.

Avg rate Δx/Δt = -Δ[R]/Δt = +Δ[p]/Δt

2. Instantaneous rate of reaction- The rate of reaction measured at a particular time is called instantaneous rate of reaction.

Instantaneous rate dx/dt= -d[R]/dt=+d[P]/dt

FACTORS AFFECTING RATE OF REACTION-

1. Concentration of reactant

2. Surface area

3. Temperature

4. Nature of reactant

5. Presence of catalyst

6. Radiation

RATE CONSTANT (k)- It is equal to the rate of reaction when molecular concentration of reactant is at unity.

RATE LAW- The rate of reaction is directly proportional to the product of concentration of reactant and each concentration is raised to some power which may or may not be equal to stereochemistry experimentally.

For a reaction

aA+bB → cC+dD

Rate law = k[A]p[B]q                                                                                                                                       Where powers P and Q are determined experimentally

MOLECULARITY – The total no. of reactants taking part in elementary chemical reaction is called molecularity.

ORDER OF REACTION- The sum of powers to which the concentrations terms are raised in a rate law expression is called order of reactions. For above case order = P+Q: orders of rn is determined experimentally

HALF-LIFE PERIOD- The time during which the concentration of the reactant is reduced to half of its initial concentration is called half-life period.

ACTIVATION ENERGY- The minimum extra amount of energy absorbed by reactant molecules so that their energy becomes equal to the threshold energy is called activation energy.

Activation energy = Threshold energy – kinetic energy

TEMPERATURE COEFFICIENT- The ratio of rate constant at two temperatures having difference of 100C is called temperature coefficient.

Temperature coefficient = Rate constant at T+100C/Rate constant at T0C

Arhenius Equation-

K= Ae-Ea/RT

K-rate constant

A-Arrhenius energy

Ea-Activation energy

R- Rate constant

T-Temperature

Log K = Log A- Eq / 2.303RT

Energy of activation can be evaluated as

1. Log [K2/K1] = Ea(1/T1-1/T2)/ 2.303RT

Log [K2/K1] = Ea(1/T1-1/T2)/ 19.15

 Please click the link below to download pdf file for CBSE Class 12 Chemistry notes and questions for Chemical Kinetics Part B.

Tags: 

 


Click to View or Download pdf file
Click for more Chemistry Study Material

Latest NCERT & CBSE News

Read the latest news and announcements from NCERT and CBSE below. Important updates relating to your studies which will help you to keep yourself updated with latest happenings in school level education. Keep yourself updated with all latest news and also read articles from teachers which will help you to improve your studies, increase motivation level and promote faster learning

CBSE Reduced Syllabus Class 11 and 12

CBSE has announced major reduction in the syllabus for class 11 and class 12. There has been major changes too in the main syllabus for class 11 and 12. The prevailing health emergency in the country and at different parts of the world as well as the efforts to contain...

Cogito and The Question Book A series on Thinking skills by CBSE

The Board has dedicated this academic session 2020-21 for ‘Competency Based Learning’. Skills connected to Critical & Creative thinking, Problem Solving, Collaboration and Communication are core to successful living in the 21st Century. To focus on the importance...

Procedure for correction in Name and Date of Birth

Procedure for correction in Name and Date of Birth in CBSE records Name Change: Applications regarding changes in name or surname of candidates will be considered provided the changes have been admitted by the Court of law and notified in the Government Gazette before...

Board Exams Class 10 and Class 12 Datesheet 2020

CBSE has announced the datesheet for the remaining exams of class 10 and class 12 exams. The exams are going to start in July. The class 10 and 12th board exams will be conducted for the remaining 29 papers from July 1 to July 15, 2020, at various centers nominated by...

CBSE advisory on student marks

CBSE has issued a public advisory for all students to be careful from unscrupulous persons impersonating themselves as officers/officials of CBSE. These people have been contacting parents and have been telling them that they have access to student marks data for Board...

Class 12 Board Exams Datesheet Announced

CBSE has announced the datesheet of the remaining class 12 board exams, see below:  

×
Studies Today