To a 25 mL `H_(2)O_(2)` solution excess of an acidified solution of
potassium iodide was added. The iodine liberated required 20 mL of 0.3 N sodium thiosulphate solution Calculate the volume strength of `H_(2)O_(2)` solution.

Explanation

To solve the problem, we will follow these steps:

### Step 1: Calculate the milliequivalents of sodium thiosulfate (Na2S2O3)
We know that:
- Volume of Na2S2O3 solution = 20 mL
- Normality of Na2S2O3 solution = 0.3 N

Using the formula for milliequivalents:
...