What is chemical kinetics?
Chemical kinetics is a very interesting branch of physical Chemistry. The first quantitative investigation in chemical kinetics has been performed by German scientist Ludwig Ferdinand Wilhelmy (1812–1864) in 1850 who utilized polarimetry to study the acid-catalyzed conversion of sucrose. It basically deals with the study of the rate of chemical reaction or conversions of reactants into the products, that occur according to the certain mechanism, which is known as the reaction mechanism. The change in concentration of some solution with respect to time is expressed as the rate of a chemical reaction. It is evident that chemical reactions are also the subject of study of many other physicochemical and chemical branches, such as chemical thermodynamics, analytical chemistry, technology, and many more. Don’t get confused between the term thermodynamic and Chemical kinetics. It is often observed that students get confused with these two. You must understand that thermodynamics involves the study of overall energy change between the final stage and the initial of the procedure. This change can result appear after infinite time; the thermodynamics does not directly involve the study of the reaction rate of a chemical reaction.
Before understanding the chemical kinetics, you must know what is a chemical reaction. By definition, a chemical reaction is a process in which chemical elements are transformed into other elements, which means the chemical bonds are formed and broken which changes in the relative positions of atoms in molecules. Simultaneously, there is a change in the arrangements of the electrons which form the chemical bonds. Similarly, a reaction mechanism is a branch that deals with the speeds and movements of atoms and electrons. The detailed mechanism by which a chemical process takes place is commonly known as the reaction pathway or reaction path.
Now, let’s understand why chemical kinetics is important?
A proper understanding of chemical kinetics is very important. It helps you to understand the reactions, as well as its practical implications. For instance, in industry, reactions are performed in reactors in which chemical compounds are blended together, possibly heated and stirred for a while, and then proceeded to the next step of the procedure. It is very significant to know for how long to perform the reaction at one stage before proceeding to the next stage, to ensure that reaction has finished before initiating the next steps. It is very important to know such parameters to yield the maximum efficiency of a chemical process.
Many chemical procedures can be improved by understanding how a reaction takes place. For instance, if it is known that a particular intermediate is involved in a chemical reaction, the use of conditions (such as certain temperature level, pressure or reagents) which are incompatible with that intermediate might be avoided. In addition, reagents or catalyst might be involved that would make certain steps in the reaction takes place more quickly and easily.
kinetic studies are not only important in the industry but are also utilized to understand biological procedures, especially enzyme-catalyzed reactions. They also play a significant role in atmospheric and chemistry environmental, which help us to understand a variety of issues ranging from the cascade of reactions involved in the ozone cycle to the fate of prescription pharmaceuticals in wastewater.
Now, how to calculate the rate of reaction?
- Reaction rate is calculated by means of the following formula
- Reaction rate = Δ[C]/Δt, where Δ[C] is the change in product concentration during time period Δt.
- The rate of reaction can be observed by looking at the disappearance of a reactant or the formation of a product with respect to the time.
- If a reaction forms a gas such as carbon dioxide or oxygen, there are two methods to find the reaction rate: by means of a gas syringe to measure the gas produced or calculating the reduction in the mass of the reaction solution.
- If the reaction generates a precipitate, the amount generated precipitates can be utilized to calculate the reaction rate by measuring how long it takes for the production of precipitate to obscure the visibility of a cross through a conical flask.
I hope now you understand the meaning of chemical kinetics and its importance. Understand the rate of reaction is very important to conduct an efficient chemical reaction.