The binary compounds of oxygen with other elements are called oxides. They are classified depending either upon their acid-base characteristics or on the basis of oxygen content.
(a) Normal oxides : These oxides which contain oxygen atom as permitted by the normal oxidation number, i.e., `-2` normal oxide may be acidic, basic, amphoteric or neutral.
(b) Polyoxides : The oxides which contain oxygen atoms different than those permitted by the normal oxidation number of `-2`.
(i) Peroxides : Two oxygen atoms are linked to each other and oxyegen has `-1` oxidation number. They contain `(O -O)^(2-)` unit.
(ii) Superoxodes : These oxides contain `(O-O)^(-1)` unit, i.e., each O-atom has oxidation number `-1//2`.
(c) Suboxides : These contain low content of oxygen than expected.
(d) Mixed oxides : These oxides are made of two simpler oxides.
Which of the following oxides is paramagnetic in nature ?

Options

A. `KO_2`
B. `BaO_2`
C. `H_2 O`
D. `CO_2`

Answer

To determine which of the given oxides is paramagnetic in nature, we will analyze the provided options based on their classification and oxidation states.

### Step 1: Understand the classification of oxides
- Oxides can be classified into normal oxides, polyoxides, peroxides, superoxides, suboxides, and mixed oxides.
- Superoxides are a type of polyoxide where oxygen has an oxidation state of -1/2.

### Step 2: Identify the oxidation state in the options
- We need to find out the oxidation states of oxygen in the given options to identify if any of them is a superoxide, which is known to be paramagnetic due to the presence of unpaired electrons.

### Step 3: Analyze each option
1. **KO2 (Potassium Superoxide)**:
- The oxidation state of potassium (K) is +1.
- Let the oxidation state of oxygen be x.
- The compound is neutral, so:
\[ +1 + 2x = 0 \implies 2x = -1 \implies x = -\frac{1}{2} \]
- Since the oxidation state of oxygen is -1/2, KO2 is a superoxide and is paramagnetic.

2. **H2O (Water)**:
- The oxidation state of hydrogen (H) is +1.
- Let the oxidation state of oxygen be y.
- The compound is neutral, so:
\[ 2(+1) + y = 0 \implies y = -2 \]
- Water is a normal oxide and is diamagnetic.

3. **H2O2 (Hydrogen Peroxide)**:
- The oxidation state of hydrogen (H) is +1.
- Let the oxidation state of oxygen be z.
- The compound is neutral, so:
\[ 2(+1) + 2z = 0 \implies 2z = -2 \implies z = -1 \]
- Hydrogen peroxide is a peroxide and is diamagnetic.

4. **CO2 (Carbon Dioxide)**:
- The oxidation state of carbon (C) is +4.
- Let the oxidation state of oxygen be w.
- The compound is neutral, so:
\[ +4 + 2w = 0 \implies 2w = -4 \implies w = -2 \]
- Carbon dioxide is a normal oxide and is diamagnetic.

### Step 4: Conclusion
- Among the options analyzed, KO2 (Potassium Superoxide) is the only oxide that is paramagnetic due to the presence of unpaired electrons in the superoxide ion (O2^-).

### Final Answer
The oxide that is paramagnetic in nature is **KO2**.

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