Examine the following resonating structures of formic acid and arrange them in decreasing order of stability :
`H-overset(O)overset(||)C-underset(* *)overset(* *)OHharrH-overset(""^(Ɵ)O)overset(|)C=overset(o+)O-H-harrH-underset(o+)overset("" ^(Ɵ)O)overset(|)C-OHharrH-underset(Ɵ)overset(O^(o+))overset(|)C-OH`

Options

A. `IIgtIgtIIIgtIV`
B. `IgtIIgtIIIgtIV`
C. `IIIgtIIgtIVgtI`
D. `IVgtIIIgtIgtII`

Explanation

To determine the stability of the resonating structures of formic acid, we will analyze each structure based on the following criteria:

1. **Charge Neutrality**: Neutral molecules are generally more stable than charged ones.
2. **Octet Rule**: Structures where all atoms have a complete octet are more stable.
3. **Electronegativity**: Negative charges are more stable on more electronegative atoms.

### Step-by-Step Solution:

**Step 1: Identify the Structures**
We have four resonating structures to analyze. Let's denote them as:
- Structure 1: Neutral structure (HCOOH)
- Structure 2: Positive charge on carbon and negative charge on oxygen
- Structure 3: Negative charge on oxygen and positive charge on carbon
- Structure 4: Negative charge on carbon and positive charge on oxygen

**Step 2: Analyze Structure 1**
- Structure 1 is neutral (HCOOH).
- It has a complete octet for all atoms (C, O, H).
- **Stability**: Most stable due to neutrality and complete octet.

**Step 3: Analyze Structure 2**
- Structure 2 has a positive charge on carbon and a negative charge on oxygen.
- Both oxygen and carbon have complete octets.
- **Stability**: More stable than charged structures but less stable than Structure 1.

**Step 4: Analyze Structure 3**
- Structure 3 has a negative charge on oxygen and a positive charge on carbon.
- The octet is complete for both atoms.
- Since the negative charge is on the more electronegative oxygen atom, this structure is relatively stable.
- **Stability**: Less stable than Structure 1 and Structure 2.

**Step 5: Analyze Structure 4**
- Structure 4 has a negative charge on carbon and a positive charge on oxygen.
- The octet is not complete for carbon.
- The negative charge on carbon (less electronegative) makes this structure the least stable.
- **Stability**: Least stable due to incomplete octet and unfavorable charge distribution.

### Final Order of Stability
Based on the analysis:
1. Structure 1 (Neutral - HCOOH)
2. Structure 2 (Complete octet, charges on C and O)
3. Structure 3 (Complete octet, negative charge on O)
4. Structure 4 (Incomplete octet, negative charge on C)

Thus, the order of stability from most stable to least stable is:
**1 > 2 > 3 > 4**