3.55 g sample of bleaching powder suspended in `H_(2)O` was treated with enough acetic acid and KI solution. Iodine thus liberated required 80 mL of 0.2 N hypo for titration. Calculate the % of available chlorine.

Explanation

To solve the problem of calculating the percentage of available chlorine in a sample of bleaching powder, we will follow these steps:

### Step 1: Write the balanced chemical equations
The reaction of bleaching powder (Ca(OCl)₂) with acetic acid (CH₃COOH) and potassium iodide (KI) can be represented as:
\[ \text{Ca(OCl)}_2 + 2 \text{CH}_3\text{COOH} + 2 \text{KI} \rightarrow \text{I}_2 + \text{CaCl}_2 + 2 \text{CH}_3\text{COOK} + 2 \text{H}_2\text{O} \]

The iodine (I₂) produced is then titrated with sodium thiosulfate (hypo, Na₂S₂O₃):
\[ \text{I}_2 + 2 \text{Na}_2\text{S}_2\text{O}_3 \rightarrow \text{Na}_2\text{S}_4\text{O}_6 + 2 \text{NaI} \]
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