Final answer:
The dichromate ion in acidified K₂Cr₂O₇ solution acts as an oxidizing agent, therefore when it is added to Sn2+ salts, Sn²⁺ is oxidized to Sn⁴⁺. The correct answer is option: C Sn⁴⁺
Step-by-step explanation:
When acidified K₂Cr₂O₇ solution is added to Sn²⁺ salts, the Sn²⁺ is oxidized to Sn⁴⁺. This is a redox reaction where dichromate ion (Cr₂O₇2−) acts as an oxidizing agent and oxidizes the Sn²⁺ to Sn⁴⁺.
In the context of the provided reactions, we see that dichromate and related chromium species are capable of changing oxidation states, depending on the conditions. For example:
(c) The reaction 2HCrO₄ (aq) → Cr₂O₇²⁻ (aq) + H₂O(l) shows the equilibrium between chromate and dichromate ions in acid solution.
(d) The reaction 3Cr₂+ (aq) + CrO₄²⁻ (aq) + 8H₃O+ (aq) → suggests that chromium compounds can undergo redox transformations.
The question's answer is that Sn²⁺ changes to Sn⁴⁺ when acidified K₂Cr₂O₇ is added.