WORLD OF RASAYAN

Search This Blog

Featured Articles

Get link
Facebook
X
Pinterest
Email
Other Apps

Get link
Facebook
X
Pinterest
Email
Other Apps

Comments

New comments are not allowed.

Labels

Acids and Bases
Atomic Structure
Chemical bonds
Chemical Kinetics
Electronic effects
Friction story
Ideal Gas
Inorganic Chemistry
Interdisciplinary
Intermolecular Forces

Natural compounds
NCERT
Organic Chemistry
Periodic table
Physical
Physical Chemistry
question answer
Radioactivity
Reaction Mechanism
Rearrangement
Thermodynamics

Show more Show less

Atomic Structure mock test

Atomic Structure Mock Test Atomic Structure Mock Test Submit Test Retake Test

Introduction to Chemical kinetics

Introduction Chemical kinetics is the branch of physical chemistry which deals with a study of the speed of chemical reactions. Such studies also enable us to understand the mechanism by which the reactions occur. In chemical equilibria, only the initial and final states were considered, the energy relations between the reactants and the products being governed by thermodynamics where the time or the intermediate states were of no concern. In chemical kinetics the rate of the reaction process is followed; in other words, the time variable is introduced. This, we shall see, reveals not only the influence of different factors on the progress of the reaction but it also throws light on the mechanism through which reactant molecules are transformed into products. It is a common knowledge that apart from the chemical nature, the rates of reaction depend on the concentration of reactants and the temperature. It will be seen later that many reaction rates are greatly influenced by the...

Kinetics of First and Second Order Reactions

First Order Kinetics A reaction of the first order is represented as: X → Y where X is the reactant and Y the product. The rate of the reaction will be directly proportional to the concentration, i.e., − d C d t = k C - \frac{dC}{dt} = kC \tag{XXII.3} in which C is the concentration of the reactant at any time t and k is a constant, called the velocity constant or specific reaction rate . Rewriting, − d C C = k d t - \frac{dC}{C} = kdt On integration, − ln ⁡ C = k t + z ( constant ) - \ln C = kt + z \quad (\text{constant}) If at the start of the reaction, the initial concentration of the reactant is C₀ , then we have at t = 0 , C = C 0 C = C₀ Substituting in, − ln ⁡ C 0 = z ⇒ − ln ⁡ C = k t − ln ⁡ C 0 - \ln C₀ = z \Rightarrow -\ln C = kt - \ln C₀ i.e., ln ⁡ C 0 C = k t , or C C 0 = e − k t \ln \frac{C₀}{C} = kt, \quad \text{or} \quad \frac{C}{C₀} = e^{-kt} Hence, C = C 0 e − k t The concentration (C) therefore diminishes exponentially with time. We may also write,...

Powered by Blogger