In the analytical technique called electrogravimetry, electrolysis is used to separate the analyte from a solution by depositing it on an inert electrode. The electrode is weighed before and after the experiment to find the mass of analyte deposited. A 0.122-g sample of a copper-zinc alloy was treated with concentrated sulfuric acid to produce a solution containing copper(II) and zinc(II) sulfates.

The platinum cathode used in the electrolysis of this solution increased in mass by 0.073 g after exhaustive electrolysis.

(a) Which metal was deposited on the cathode during the electrolysis? Write the balanced equation for the electrolysis reaction.

(b) What was the mass percentages of copper and zinc in the alloy sample?