Question

What is the oxidation state of Chlorine in \( Cl_2O_7 \)?

• A. \(+1\)
• B. \(+3\)
• C. \(+5\)
• D. \(+7\)

Hint:

To find oxidation states quickly:
• Oxygen generally has oxidation state \( -2 \).
• Multiply oxidation states by the number of atoms.
• The total for a neutral molecule must equal \(0\).

Answer 1

The Correct Option is D

Concept: The oxidation state (oxidation number) of an element represents the hypothetical charge it would have if all bonds were completely ionic. Some important rules used to determine oxidation states are:
• Oxygen usually has an oxidation state of \( -2 \).
• The sum of oxidation states of all atoms in a neutral molecule is \(0\).

Step 1: Assign oxidation states to known elements. In the compound \( Cl_2O_7 \), oxygen has an oxidation state of \( -2 \). There are \(7\) oxygen atoms: \[ 7 \times (-2) = -14 \]

Step 2: Let the oxidation state of chlorine be \(x\). Since there are \(2\) chlorine atoms: \[ 2x + (-14) = 0 \] \[ 2x = 14 \] \[ x = +7 \]

Step 3: Interpretation. Thus, the oxidation state of chlorine in \( Cl_2O_7 \) is \( +7 \).