Question

Consider the following redox reaction between 50. mL of a 0.0500 M Sn2+ solution with 0.100 M Tl3+ if the solution is in a 1.0 M HCl solution (you can disregard the HCl, it’s acting as an electrolyte).

1. Write out your balanced reaction ensuring you’re taking into account the electrons being transferred

2. Determine the volume of thallium needed to reach the equivalence point.

3. Determine the standard potential of the cell

4. Setup a data table determining the concentration of each ion after every 5.0 mL of titrant added

5. Using your data table, and the following modified Nernst equation, determine the measured cell potential

Answer 1

1. Write out your balanced reaction ensuring you’re taking into account the electrons being transferred.

Sn ²⁺ ----------> Sn ⁴⁺ + 2e^- E° = - 0.154 V
50.0mL
0.05 M

2e^- + Tl ³⁺ -------------> Tl ¹⁺  E° = +1.25 V
0.1 M

2. Determine the volume of thallium needed to reach the equivalence point.

The following expression must be met in any redox valuation:

3. Determine the standard potential of the cell.

Sn ²⁺ ----------> Sn ⁴⁺ + 2e^- E°_oxd = - 0.154 V
2e^- + Tl ³⁺ -------------> Tl ¹⁺  E°_red = +1.25 V

E° = (-0.154 V)+(1.250 V )
E°=+1.096 V