What happens when `SO_2` is passed through caustic soda solution ?

Explanation

When sulfur dioxide (SO₂) is passed through a caustic soda solution (sodium hydroxide, NaOH), a chemical reaction occurs. Here’s the step-by-step breakdown of the process:

### Step 1: Identify the Reactants
The reactants in this reaction are:
- Sulfur dioxide (SO₂)
- Caustic soda (sodium hydroxide, NaOH)

### Step 2: Write the Initial Reaction
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