Question

In which of the following is the oxidation state of oxygen \(+2\)?

• A. F$_2$O
• B. Cl$_2$O
• C. Na$_2$O$_2$
• D. Na$_2$O

Hint:

Oxygen usually has \(-2\), but in peroxides it’s \(-1\), in superoxides \(-\tfrac{1}{2}\), and in oxygen difluoride it’s \(+2\).

Answer 1

The Correct Option is A

Step 1: Assign oxidation states.
In \( \mathrm{F_2O} \) (oxygen difluoride), fluorine is more electronegative and has \(-1\) each. Let O be \(x\):
\( x + 2(-1) = 0 \Rightarrow x = +2 \).
Step 2: Eliminate others.
Cl$_2$O: O is \(-2\) (Cl is \(+1\)).
Na$_2$O$_2$: Peroxide, O is \(-1\).
Na$_2$O: Oxide, O is \(-2\).
Step 3: Conclusion.
Only F$_2$O has oxygen in the \(+2\) state.