Which of the following statements are correct?
1. A `sigma` bond is stronger than a `pi` bond
2. A covalent bond is stronger than a hydrrogen bond
3. HF is more polar than HCl
4. There is one electrovalent bond and three covalent bonds in methylene chloride Select the correct answer using the codes given below

Options

A. 2, 3 and 4
B. 1 and 3
C. 1, 2 and 4
D. 1, 2 and 3

Answer

To determine which of the statements are correct, we will analyze each statement one by one.

### Step 1: Analyze Statement 1
**Statement 1:** A sigma bond is stronger than a pi bond.

**Explanation:**
- A sigma (σ) bond is formed by the head-on (axial) overlap of atomic orbitals, which allows for a stronger bond due to the direct overlap of electron density.
- A pi (π) bond is formed by the side-to-side (lateral) overlap of p orbitals, which is generally weaker than a sigma bond because the overlap is less effective.

**Conclusion:** This statement is **correct**.

### Step 2: Analyze Statement 2
**Statement 2:** A covalent bond is stronger than a hydrogen bond.

**Explanation:**
- A covalent bond involves the sharing of electrons between atoms, resulting in a strong bond (bond energy typically around 300-400 kJ/mol).
- A hydrogen bond is a weaker interaction that occurs due to the attraction between a hydrogen atom covalently bonded to an electronegative atom (like O or N) and another electronegative atom. The energy of hydrogen bonds is typically around 20-40 kJ/mol.

**Conclusion:** This statement is **correct**.

### Step 3: Analyze Statement 3
**Statement 3:** HF is more polar than HCl.

**Explanation:**
- The polarity of a molecule is determined by the difference in electronegativity between the atoms involved.
- Fluorine (F) is more electronegative than chlorine (Cl). Therefore, the bond in HF is more polar than the bond in HCl because the electron density is pulled more towards F than Cl.

**Conclusion:** This statement is **correct**.

### Step 4: Analyze Statement 4
**Statement 4:** There is one electrovalent bond and three covalent bonds in methylene chloride.

**Explanation:**
- Methylene chloride (CH2Cl2) consists of two hydrogen atoms and two chlorine atoms bonded to a central carbon atom.
- All the bonds in methylene chloride are covalent bonds. There are no ionic (electrovalent) bonds present in this molecule.

**Conclusion:** This statement is **incorrect**.

### Final Conclusion
The correct statements are **1, 2, and 3**.

### Summary of Correct Statements:
- Statement 1: Correct
- Statement 2: Correct
- Statement 3: Correct
- Statement 4: Incorrect