Question

A reaction involving \( K_2 \text{Cr}_2 \text{O}_7 \) is treated with hydrogen sulfide. The oxidation number of chromium changes from +3 to +6, +2, or remains unchanged. Which of the following correctly reflects the change in oxidation number?

• A. Chromium remains unchanged.
• B. Oxidation number decreases from +6 to +2.
• C. Oxidation number decreases from +6 to +3.
• D. Chromium undergoes reduction from +3 to +2.

Hint:

Reduction involves the decrease of the oxidation state, and hydrogen sulfide is a common reducing agent.

Answer 1

The Correct Option is B

Hydrogen sulfide reduces chromium from +6 oxidation state in \( K_2 \text{Cr}_2 \text{O}_7 \) to +2 oxidation state.
Final Answer: \[ \boxed{\text{Oxidation number decreases from +6 to +2.}} \]