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NEET CHEMISTRYThe d-and f-Block ElementsEasy

Question

Which one of the following statements is correct when SO2\text{SO}_2 is passed through acidified K2Cr2O7\text{K}_2\text{Cr}_2\text{O}_7 solution?

A

The solution is decolourized

B

SO2\text{SO}_2 is reduced

C

Green Cr2(SO4)3\text{Cr}_2(\text{SO}_4)_3 is formed

D

The solution turns blue

Step-by-Step Solution

When SO2\text{SO}_2 gas is passed through an acidified solution of potassium dichromate (K2Cr2O7\text{K}_2\text{Cr}_2\text{O}_7), it acts as a reducing agent. It reduces the orange dichromate ion (Cr2O72−\text{Cr}_2\text{O}_7^{2-}) to green chromium(III) ion (Cr3+\text{Cr}^{3+}), while itself being oxidised to sulphate ion (SO42−\text{SO}_4^{2-}). The overall reaction is: K2Cr2O7+H2SO4+3SO2→K2SO4+Cr2(SO4)3+H2O\text{K}_2\text{Cr}_2\text{O}_7 + \text{H}_2\text{SO}_4 + 3\text{SO}_2 \rightarrow \text{K}_2\text{SO}_4 + \text{Cr}_2(\text{SO}_4)_3 + \text{H}_2\text{O}. Therefore, green chromium(III) sulphate, Cr2(SO4)3\text{Cr}_2(\text{SO}_4)_3, is formed.

Exam Context & Concepts Covered

This question aligns with the NEET CHEMISTRY syllabus, specifically targeting concepts from The d-and f-Block Elements. Mastering this topic is crucial for scoring well in the upcoming medical entrance examinations. Solving conceptually related problems will help you understand the nuances of these concepts and improve your problem-solving speed.

CHEMISTRYThe d-and f-Block Elementsfollowingstatementscorrecttextsopassed

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