By starting with 0.5 moles of sodium peroxide how many moles of dioxygen gas can be obtained by dropping excess of acidified potassium permanganate solution on it ?

Options

A. 0.125 mole
B. 1 mole
C. 0.25 mole
D. 0.5 mole

Answer

To solve the problem of how many moles of dioxygen gas can be obtained from 0.5 moles of sodium peroxide when reacting with excess acidified potassium permanganate, we will follow these steps:

### Step 1: Write the balanced chemical equation
The reaction involves sodium peroxide (Na2O2) and potassium permanganate (KMnO4) in an acidic medium. The balanced chemical equation for this reaction is:

\[ 5 \text{Na}_2\text{O}_2 + 2 \text{KMnO}_4 + 8 \text{H}_2\text{SO}_4 \rightarrow 5 \text{O}_2 + 2 \text{MnSO}_4 + 5 \text{Na}_2\text{SO}_4 + K_2\text{SO}_4 + 8 \text{H}_2\text{O} \]

### Step 2: Analyze the stoichiometry
From the balanced equation, we can see that:
- 5 moles of sodium peroxide produce 5 moles of dioxygen (O2).

### Step 3: Determine the amount of dioxygen produced
Since we have 0.5 moles of sodium peroxide, we can set up a proportion based on the stoichiometry of the reaction:

\[ \text{If } 5 \text{ moles of Na}_2\text{O}_2 \text{ produce } 5 \text{ moles of O}_2, \]
\[ \text{Then } 0.5 \text{ moles of Na}_2\text{O}_2 \text{ will produce } \frac{5 \text{ moles of O}_2}{5 \text{ moles of Na}_2\text{O}_2} \times 0.5 \text{ moles of Na}_2\text{O}_2 = 0.5 \text{ moles of O}_2. \]

### Conclusion
Thus, from 0.5 moles of sodium peroxide, we can obtain **0.5 moles of dioxygen gas**.

### Final Answer
0.5 moles of dioxygen gas can be obtained.

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