Question

Discuss the significance of the equivalence point. What do you know about the solution at that point and how do you know it? Use your chemical knowledge to explain. ( lab for pH Measurement and Titration  by using the NaOH and cola)

Answer 1

The equivalence point is the point in a titration where the amount of titrantadded is enough to completely neutralize the analyte solution. The moles of titrant (standard solution) equal the moles of the solution with unknown concentration. This is also known as the stoichiometric point because it is where the moles of acid are equal to the amount needed to neutralize the equivalent moles of base.

Note this does not necessarily mean the acid to base ratio is 1:1. The ratio is determined by the balanced acid-base chemical equation.

The equivalence point is not the same as the endpoint of a titration. The endpoint refers to the point at which an indicator changes color. Using the endpoint to calculate equivalence naturally introduces error.n the equivalence point we have solution containing pure salt that is a product of the neutralization reaction occurring during titration. Thus calculation of the equivalence point pH is identical with the calculation of the pH of the salt solution.