Oxidation number of Mn in `K_(2)MnO_(4)` is

Answer

To find the oxidation number of manganese (Mn) in the compound \( K_2MnO_4 \), we can follow these steps:

### Step 1: Assign oxidation numbers to known elements
- The oxidation number of potassium (K) is \( +1 \).
- The oxidation number of oxygen (O) is \( -2 \).

### Step 2: Set up the equation
Let the oxidation number of manganese (Mn) be \( x \). The formula for the compound is \( K_2MnO_4 \), which contains:
- 2 potassium atoms
- 1 manganese atom
- 4 oxygen atoms

Using the oxidation numbers:
- Contribution from potassium: \( 2 \times (+1) = +2 \)
- Contribution from manganese: \( x \)
- Contribution from oxygen: \( 4 \times (-2) = -8 \)

### Step 3: Write the equation for the overall charge
Since the compound is neutral, the sum of the oxidation numbers must equal zero:
\[ 2 + x - 8 = 0 \]

### Step 4: Solve for \( x \)
Rearranging the equation:
\[ x - 6 = 0 \]
\[ x = 6 \]

### Conclusion
The oxidation number of manganese (Mn) in \( K_2MnO_4 \) is \( +6 \).

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