Distribution coefficient of an organic acid between water and benzene is \(4.1\) is favour of \(\mathrm{C}_{6} \mathrm{H}_{6}\). If \(5 \mathrm{~g}\) of the acid is distributed in between 50 \(\mathrm{mL}\) of benzene and \(100 \mathrm{~mL}\) of water, calculate the concentration of the acid in two solvents.

Equilibrium is a fundamental concept in chemistry that describes the state in which the rates of the forward and reverse reactions are equal, resulting in no overall change in the concentration of reactants and products over time. This dynamic balance can occur in a closed system where both the reactants and products are present. Imagine a simple seesaw that's perfectly balanced: movements will happen on both sides, but the overall position stays the same.

When substances react, they can form products, and those products can sometimes revert back into reactants. At equilibrium, these two processes occur at the same rate, and the amounts of each substance become constant. This idea is essential when dealing with the distribution coefficient in solvent extraction, as the coefficient is a measure of how a compound distributes itself between two immiscible solvents at equilibrium.

Solvent extraction, also known as liquid-liquid extraction, is a technique to separate compounds based on their relative solubilities in two different immiscible liquids. Generally, this involves shaking a solution with a solvent that is immiscible (not mixable) with the rest of the liquids in the container, allowing the compound of interest to move into the solvent layer in which it is more soluble. Once the two layers are separated, you can remove the solvent containing the compound of interest for further use.

Understanding how a compound partitions itself between these layers is crucial and is called the 'distribution coefficient' or 'partition coefficient.' It allows scientists to predict where a compound will concentrate in a two-phase system. When you're working to extract a particular substance, knowing this coefficient can mean the difference between a successful and an unsuccessful separation.

Concentration calculation involves determining the amount of solute present in a given volume of solution. It’s a key concept in various chemical processes, including solvent extraction. In the context of the given exercise, concentration helps in quantifying how much of the organic acid is present in each solvent. After you have set up the equilibrium equation based on the distribution coefficient, you solve for the unknown concentration, typically expressed in units such as grams per milliliter (g/mL).

When you calculate concentration, you're essentially finding out how 'strong' or 'weak' a solution is. For students, getting comfortable with concentration calculations means they can tackle problems ranging from simple dilutions to more complex distribution between phases in a system. Once the concentration is calculated, it can further be used to determine other important solution properties or quantities needed in both academic and practical laboratory settings.