Explain the significance of the stoichiometric point in titrations.

The stoichiometric point in titrations is the exact point where the reactants are in their correct stoichiometric proportions.

In a titration, the stoichiometric point, also known as the equivalence point, is the moment when the quantity of the titrant (the solution of known concentration) is just enough to react completely with the analyte (the solution of unknown concentration). This point is significant because it allows us to determine the exact concentration of the analyte, which is the primary goal of a titration.

The stoichiometric point is determined by the stoichiometry of the reaction between the titrant and the analyte. For example, in a reaction with a 1:1 stoichiometry, the stoichiometric point is reached when the number of moles of the titrant equals the number of moles of the analyte. In a reaction with a 1:2 stoichiometry, the stoichiometric point is reached when the number of moles of the titrant is twice the number of moles of the analyte.

The stoichiometric point is usually detected by a sudden change in the physical property of the solution, such as its pH or its electrical conductivity. This change is often indicated by a colour change in an added indicator, or by a sudden change in the reading of a pH meter or a conductivity meter. The volume of the titrant required to reach the stoichiometric point is then used to calculate the concentration of the analyte.

In summary, the stoichiometric point in titrations is a crucial concept in analytical chemistry. It represents the point at which the reactants are in their correct stoichiometric proportions, allowing the concentration of an unknown solution to be accurately determined. Understanding this concept is essential for performing successful titrations and for interpreting the results correctly.