Identify (A) and (B) in the following:
`KO_(2)+S overset(Delta)rarr (A)`
`(A)+BaCI_(2)rarr underset("White ppt.")(B)`

Explanation

To solve the problem, we need to identify the compounds (A) and (B) in the given reactions. Let's break it down step by step.

### Step 1: Identify the first reaction
The first reaction given is:
\[ \text{KO}_2 + \text{S} \overset{\Delta}{\rightarrow} (A) \]

- **KO₂** is potassium superoxide.
- When potassium superoxide reacts with sulfur (S) upon heating, it forms potassium sulfate.
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