Question

What is the oxidation number of carbon in methanal?

• A. -2
• B. +2
• C. zero
• D. +4

Hint:

In neutral molecules, always set the sum of oxidation states to 0.

Answer 1

The Correct Option is C

Step 1: Understanding the Question:
We need to calculate the oxidation state of carbon in methanal (formaldehyde, \( \text{HCHO} \)).

Step 2: Key Formula or Approach:
The sum of oxidation numbers in a neutral molecule is zero.
Standard values: \( \text{H} = +1 \), \( \text{O} = -2 \).

Step 3: Detailed Explanation:
Molecular formula: \( \text{H}_2\text{CO} \).
Let the oxidation state of C be \( x \).
\[ 2(+1) + x + 1(-2) = 0 \]
\[ 2 + x - 2 = 0 \]
\[ x = 0 \]

Step 4: Final Answer:
The oxidation number of carbon in methanal is zero.