Question

What is the oxidation number of Manganese (Mn) in the compound \( KMnO_4 \)?

• A. \(+4\)
• B. \(+6\)
• C. \(+7\)
• D. \(+2\)

Hint:

In most compounds oxygen has oxidation number \( -2 \), which helps quickly determine the oxidation state of the central atom.

Answer 1

The Correct Option is C

Step 1: Understanding the Question:
The goal is to determine the unknown oxidation state of a transition metal in a neutral molecule.
The topic is Redox Reactions.
Step 2: Key Formula or Approach:
The sum of oxidation numbers of all atoms in a neutral compound must be zero.
Standard oxidation states: \( K = +1 \), \( O = -2 \).
Step 3: Detailed Explanation:
Let the oxidation state of \( Mn \) be \( x \).
The formula is \( KMnO_4 \).
Summing the oxidation states:
\[ 1(K) + 1(Mn) + 4(O) = 0 \]
\[ (+1) + x + 4(-2) = 0 \]
\[ +1 + x - 8 = 0 \]
\[ x - 7 = 0 \]
Step 4: Final Answer:
\[ x = +7 \]