In the reaction,
`2 KI + H_2 O + O_3 rarr 2 KOH + O_2 + A`
The compound `A` is

Options

A. `KIO_3`
B. `I_2 O_5`
C. `HIO_3`
D. `I_2`

Explanation

To determine the compound A in the reaction:

\[ 2 \text{KI} + \text{H}_2\text{O} + \text{O}_3 \rightarrow 2 \text{KOH} + \text{O}_2 + A \]

we can follow these steps:

### Step 1: Identify the Reactants and Products
The reactants in the equation are potassium iodide (KI), water (H2O), and ozone (O3). The products include potassium hydroxide (KOH), oxygen (O2), and an unknown compound A.

### Step 2: Understand the Role of Ozone
Ozone (O3) acts as an oxidizing agent in this reaction. It can oxidize potassium iodide (KI) to iodine (I2) while being reduced to oxygen (O2).

### Step 3: Analyze the Reaction
When KI is oxidized by ozone, iodine is produced. The balanced reaction shows that for every 2 moles of KI, 1 mole of O3 is used, resulting in the formation of 2 moles of KOH and 1 mole of O2.

### Step 4: Determine the Product A
From the analysis, the oxidation of iodide ions (I-) from KI leads to the formation of iodine (I2). Therefore, compound A in the reaction is iodine (I2).

### Step 5: Write the Final Equation
The balanced reaction can be summarized as follows:

\[ 2 \text{KI} + \text{H}_2\text{O} + \text{O}_3 \rightarrow 2 \text{KOH} + \text{O}_2 + \text{I}_2 \]

Thus, the compound A is I2.

### Conclusion
The correct answer for the compound A is I2.

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