Identify the correct statement

Options

A. Lead forms compounds in +2 oxidation state due to inert pair effect
B. All halogens form only negative oxidation states
C. Catenation property increases from boron to oxygen
D. Oxygen's oxidation state is - 1 in ozonides

Answer

To solve the question of identifying the correct statement, we will analyze each statement provided in the question step by step.

### Step 1: Analyze the first statement
**Statement:** Lead forms compounds in +2 oxidation state due to the inner pair effect.

**Analysis:**
- Lead (Pb) belongs to the carbon family (Group 14).
- It has four valence electrons and can exhibit +4 oxidation state.
- However, as we move down the group, the stability of the +2 oxidation state increases due to the inner pair effect, which refers to the reluctance of the s-electrons to participate in bonding.
- Therefore, lead predominantly forms compounds in the +2 oxidation state.

**Conclusion:** This statement is **true**.

### Step 2: Analyze the second statement
**Statement:** All halogens form only negative oxidation states.

**Analysis:**
- Halogens include fluorine (F), chlorine (Cl), bromine (Br), and iodine (I).
- Fluorine typically exhibits a -1 oxidation state due to its high electronegativity.
- Chlorine, bromine, and iodine can also exhibit positive oxidation states (e.g., +1, +3, +5, +7).
- Therefore, it is incorrect to say that all halogens only form negative oxidation states.

**Conclusion:** This statement is **false**.

### Step 3: Analyze the third statement
**Statement:** The catenation property increases from boron to oxygen.

**Analysis:**
- Catenation refers to the ability of an element to form chains or rings by bonding to itself.
- Carbon has the highest catenation ability, followed by silicon, germanium, and so on.
- Boron and oxygen do not exhibit significant catenation compared to carbon.
- Therefore, the catenation property does not increase from boron to oxygen; in fact, it decreases.

**Conclusion:** This statement is **false**.

### Step 4: Analyze the fourth statement
**Statement:** The oxidation state of oxygen is -1 in ozonides.

**Analysis:**
- Ozonides are represented by the formula \( O_3^- \).
- To find the oxidation state of oxygen in ozonides, we set up the equation: \( 3x = -1 \) (where x is the oxidation state of oxygen).
- Solving gives \( x = -\frac{1}{3} \), not -1.
- Therefore, the oxidation state of oxygen in ozonides is not -1.

**Conclusion:** This statement is **false**.

### Final Conclusion:
After analyzing all statements, we find that the only correct statement is the first one: **Lead forms compounds in +2 oxidation state due to the inner pair effect.**