Describe the graphical representation of second order reactions.

The graphical representation of second order reactions shows a linear relationship when plotted as 1/[A] against time.

In more detail, second order reactions are characterised by a rate of reaction that is proportional to the square of the concentration of a single reactant, or the product of the concentrations of two reactants. This is represented mathematically as rate = k[A]^2 or rate = k[A][B], where k is the rate constant, [A] and [B] are the concentrations of the reactants, and the exponents represent the order of the reaction with respect to each reactant.

When you plot the concentration of the reactant [A] against time for a second order reaction, you will not get a straight line. Instead, the graph will show a curve that gets steeper as time progresses. This is because the rate of reaction increases as the concentration of the reactant increases.

However, if you plot the reciprocal of the concentration of the reactant (1/[A]) against time, you will get a straight line. This is a characteristic feature of second order reactions. The slope of this line is equal to the rate constant k, and the y-intercept is equal to 1/[A]0, where [A]0 is the initial concentration of the reactant.

This graphical representation is a useful tool for determining the order of a reaction experimentally. By plotting the data in different ways, you can determine which order best fits the data. If a plot of 1/[A] against time gives a straight line, then the reaction is second order. If not, then the reaction is not second order.

In summary, the graphical representation of second order reactions is a plot of 1/[A] against time, which gives a straight line. This is a unique characteristic of second order reactions and is a useful tool for determining the order of a reaction experimentally.