Question

What is the number of electrons released in conversion of \(\mathrm{C}_2 \mathrm{O}_4^{2-}\) to \(\mathrm{CO}_2\) ?

• A. 2
• B. 4
• C. 6
• D. 5

Hint:

Find the change in oxidation state of carbon and multiply by the number of carbon atoms.

Answer 1

The Correct Option is A

Step 1: Understanding the Concept
Electrons released equal the total increase in oxidation number of the atoms that are oxidised.

Step 2: Oxidation numbers
In \(\text{C}_2\text{O}_4^{2-}\): \(2x + 4(-2) = -2\), so \(x = +3\).
In \(\text{CO}_2\): \(x + 2(-2) = 0\), so \(x = +4\).

Step 3: Calculation
Each carbon changes from \(+3\) to \(+4\), losing 1 electron. Two carbon atoms are present, so 2 electrons are lost.

Step 4: Half reaction
\(\text{C}_2\text{O}_4^{2-} \rightarrow 2\text{CO}_2 + 2e^{-}\)

Final Answer:
Two electrons are released in this conversion. \[ \boxed{\text{(A) }2} \]