What volume of 0.1 M `K_2Cr_2O_7` is required to oxidise 50 " mL of " 0.2 M `Cu_2S` (cuprous sulphide) in acidic medium to give `Cr^(3+),Cr^(2+)`, and `SO_2(g)`?

Explanation

To solve the problem of determining the volume of 0.1 M \( K_2Cr_2O_7 \) required to oxidize 50 mL of 0.2 M \( Cu_2S \) in acidic medium, we will follow these steps:

### Step 1: Write the Half-Reactions
The oxidation of \( Cu_2S \) involves two half-reactions:
1. The oxidation of \( Cu^+ \) to \( Cu^{2+} \):
\[ 2Cu^+ \rightarrow 2Cu^{2+} + 2e^- \]
...