Question

In acidic medium, dichromate behaves as an oxidizing agent represented as: $Cr_2O_7^{2-} + xH^+ + ye^- \rightarrow 2Cr^{3+} + zH_2O$. The values of $x$, $y$ and $z$ are respectively:

• A. 6, 7 and 14
• B. 7, 6 and 14
• C. 14, 6 and 7
• D. 14, 7 and 6
• E. 6, 12 and 7

Hint:

Dichromate is a powerful 6-electron oxidant in acidic solutions.

Answer 1

The Correct Option is C

Step 1: Concept
The reaction must be balanced by mass and charge in acidic medium.

Step 2: Meaning
Balance oxygen using $H_2O$ and hydrogen using $H^+$.

Step 3: Analysis
7 Oxygens require 7 $H_2O$ ($z=7$). 14 Hydrogens require 14 $H^+$ ($x=14$). To balance the total charge (+12 on left, +6 on right), 6 electrons are needed ($y=6$).

Step 4: Conclusion
The values are $x=14$, $y=6$, and $z=7$. Final Answer: (C)