Question

6. A) Explain why a large surface area favours a sharp endpoint during a titration.

B) Explain how bromide content in an unknown sample could be determined using Fajan’s method. Give appropriate chemical equations.

Answer 1

A) The large surface area provides the ease of titration, i.e. the complete titration, i.e. the complete neutralization of the acid by base occurs. Hence, the large surface area favors a sharp endpoint during a titration.

B) The reaction of AgNO₃ with bromide content (Br^-) can be represented as Ag⁺ + Br^- AgBr (s) Suppose that you have a sample containing an unknown quantity of bromide ions. The number of moles of bromide might be determined by titration with a silver nitrate solution of known concentration. The known silver nitrate solution is added to the unknown bromide solution until you have added exactly the same number of moles of AgNO₃ to the mixture as there are moles of bromide present. This is termed the equivalence point of the titration.