Chemical Reaction on the Basis of Order
The order of a chemical reaction is determined by the sum of the exponents on the concentrations of the reactants in the rate law expression. This order can take on various values, such as first order, second order, or even fractional order, depending on the concentrations of the reactants. The order of a reaction is an experimental quantity, meaning it is determined through experimental observations, and it can involve fractional values.
Consider a reaction with the chemical equation aA + bB→P,
And its corresponding rate law r = k[A]x[B]y,
where x and y are the partial reaction orders for reactants A and B, and k is the rate constant.
The order of the reaction is then given by x+y.
Zero Order Reaction
In the case of zero-order reactions, the rate of the reaction remains constant and is independent of the concentrations of the reactants. Changes in the concentrations do not impact the reaction rate, and intermediate states are not considered, only the initial and final states are considerd.
2NH3(g)⟶N2(g)+3H2(g)
Rate = k[NH3]0
First Order Reaction
For first-order reactions, the rate of the reaction depends on the concentration of one reactant, and the order is 1. Even if there are multiple reactants, only one of them influences the rate, while the others have zero-order concentrations.
2H2O2 ⟶ 2H2O+O2
Rate = k[H2O2]1
Second Order Reaction
In second-order reactions, the rate depends on the concentrations of two separate reactants or the square of the concentration of one reactant. The rate equation is expressed as
r = k[A]2 or r = k[A][B], reflecting the dependence on either two separate reactants or the square of one reactant’s concentration.
2NO2⟶2NO+O2
Rate = k[NO2]2
Chemical Reactions
Chemical Reaction is the disruption of existing bonds within reactant molecules and the creation of fresh bonds in product molecules, culminating in the formation of a new substance. These reactions are all around us, spanning from the biochemical processes in our bodies that extract energy from food to the source of sunlight, where chemical reactions are used to produce the light we receive.
In this article, we will understand the meaning and characteristics of Chemical Reactions. This article will cover the various types of Chemical Reactions: Combination or Synthesis Reaction, Decomposition Reaction, Single Displacement Reaction, and Double Displacement Reaction. We also discuss factors affecting the rate of Reaction and practice questions to understand this article.
Table of Content
- What is a Chemical Reaction?
- Characteristics of a Chemical Reaction
- How would we know when a Reaction has taken place?
- Chemical Equation
- Balancing a Chemical Equation
- Types of Chemical Reaction