What element is reduced in the following reaction?

Pb + SO42 - + AuCl4 - yields PbSO4 + Au + Cl-

A) Pb

B) Au

C) S

D) O

the oxidation states of the elements before and after the reaction is;

Pb oxidation state changes from 0 to + 2

SO₄²⁻ ion there's no change in the oxidation state during the reaction

Au oxidation state changes from + 3 to 0

reduction reactions are when there's a decrease in the oxidation state of the species

oxidation reactions are when theres an increase in the oxidation state of the species

the element where there's a decrease in oxidation state is Au.

Therefore Au gets reduced.

answer is B) Au