A 0.5 g sample of an iron containing mineral mainly in the form of `CuFeS_2` was reduced suitable to convert all the ferric ions into the ferrous form and was obtained as a solution. In the absence of any interfering matter, the solution required 42 " mL of " 0.1 M `K_2Cr_2O_7` solution for titration calculate the percentage of `CuFeS_2` in the mineral `(Cu=63.5,Fe=55.8)`

Explanation

To solve the problem step-by-step, we will follow these calculations:

### Step 1: Calculate the number of moles of K2Cr2O7 used in the titration.

Given:
- Volume of K2Cr2O7 solution = 42 mL
- Molarity of K2Cr2O7 = 0.1 M

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