The electrolysis of Na 2 SO 4 (aq) is conducted in two separate half-cells joined by a
Question:
The electrolysis of Na2SO4(aq) is conducted in two separate half-cells joined by a salt bridge, as suggested by the cell diagram Pt∣Na2SO4(aq)∥Na2SO4(aq)∣Pt.
(a) In one experiment, the solution in the anode compartment becomes more acidic, and that in the cathode compartment more basic, during the electrolysis. When the electrolysis is discontinued and the two solutions are mixed, the resulting solution has pH = 7. Write half-cell equations and the overall electrolysis equation.
(b) In a second experiment, a 10.00-mL sample of an unknown concentration of H2SO4(aq) and a few drops of phenolphthalein indicator are added to the Na2SO4(aq) in the cathode compartment. Electrolysis is carried out with a current of 21.5 mA (milliamperes) for 683 s, at which point, the solution in the cathode compartment acquires a lasting pink color. What is the molarity of the unknown H2SO4(aq)?
Step by Step Answer:
General Chemistry Principles And Modern Applications
ISBN: 9780132931281
11th Edition
Authors: Ralph Petrucci, Jeffry Madura, F. Herring, Carey Bissonnette