Use Table 17.1 to select (a) a reducing agent that converts Sn2+ to Sn but not Tl+...

Use Table 17.1 to select

(a) a reducing agent that converts Sn²⁺ to Sn but not Tl⁺ to Tl.

(b) an oxidizing agent that converts Hg to Hg₂ ²⁺ but not Br² to Br².

(c) a reducing agent that converts Sn⁴⁺ to Sn²⁺ but not Sn²⁺ to Sn.

Reference