Question

Consider the titration of 25.00 mL of 0.0750 M Sn²⁺ with 0.1000 M Fe³⁺ in 1 M HCl to give Fe²⁺ and Sn⁴⁺ , using a Pt electrode for the cathode and a Standard Hydrogen Electrode for the anode (connected to negative terminal of potentiometer).

e) Sketch the titration curve and indicate the equivalent pt, and the E_titr when ½ of the moles of analyte has been oxidized.

Answer 1

Let us consider the reaction involved in the redox titration,

The stoichometry of Fe(III):Sn(II)=2:1

The equivalence point E can be calculated as follows.

At equivalence point,

According to Nernst equation,

When half the moles of analyte has been oxidized, the E can be determined as follows.

The pH curve is as follows.