Greater Minds Tutors

Chemical kinetics deals with two main aspects of a chemical reaction: the rate of reaction (i.e, the speed at which the reaction occurs), and the reaction mechanism (i.e, the details of all the steps involved in the reaction). In this post, our focus shall be on the rates of chemical reactions. Rates of Reactions Rate is the degree of change of the property of a substance with respect to time. A chemical reaction is a change which involves the conversion of reactants to products, as stated below:                    A ----> B where A is the reactant and B is the product. In the above hypothetical equation, it can be said that at the beginning of the reaction at time, t = 0, the amount of A present will be 100%, while the amount of B will be 0%. After, a given time, say t1, the concentration of A will decrease, while that of B will be seen to increase. The speed at which these changes occur is said to be the rate of reaction. Therefore, the rate of a chemical reaction i

In our previous post, we looked at the overview of the rates of chemical reactions, where we studied the concepts and factors that affect the rates of reactions. In this post, we will be studying the rate law and the different orders of reaction, and how to determine them. Rate Law Consider the reaction:             mA + nB ----> Products The rate law states that the rate of a reaction is directly proportional to the active masses of the reactants. This implies that the concentration of the reacting species will determine how fast and how far a reaction can go. Using the above equation, the rate law can be expressed as:             rate & [A]^m[B]^n ..........(i)             rate = k[A]^m[B]^n ..........(ii) where, [A] = concentration of reactant A [B] = concentration of reactant B    & = sign of proportionality    k = rate constant The rate law is also known as the law of mass action. Orders of Reaction In chemical kinetics, an order is the index or power of t