Which of the following statements is not true for covalent compounds ?

Options

A. These have low melting point
B. These have less lattice energy
C. These show good solubility in organic solvents
D. These have well defined lattices

Answer

To determine which statement is not true for covalent compounds, we need to analyze the characteristics of covalent compounds. Here’s a step-by-step solution:

### Step 1: Understand Covalent Compounds
Covalent compounds are formed by the sharing of valence shell electrons between atoms. This sharing allows each atom to achieve a full outer shell, typically following the octet rule.

**Hint:** Remember that covalent bonds involve electron sharing, unlike ionic bonds which involve electron transfer.

### Step 2: Analyze the Properties of Covalent Compounds
1. **Bond Strength**: Covalent bonds are generally not as strong as ionic bonds. This results in lower melting and boiling points for covalent compounds.

**Hint:** Consider how bond strength affects physical properties like melting and boiling points.

2. **Lattice Energy**: Covalent compounds do not have high lattice energy, as they do not form a lattice structure like ionic compounds. Instead, they exist as discrete molecules.

**Hint:** Think about how lattice energy is related to the arrangement of particles in a solid.

3. **Solubility**: Covalent compounds tend to be soluble in organic solvents due to the weak intermolecular forces (like Van der Waals forces) present between their molecules.

**Hint:** Consider the types of interactions that occur in different solvents.

4. **Well-defined Lattices**: This statement is often associated with ionic compounds, which form well-defined lattice structures due to the strong electrostatic forces between oppositely charged ions. Covalent compounds, on the other hand, do not form such structures.

**Hint:** Reflect on the structural differences between ionic and covalent compounds.

### Step 3: Identify the Incorrect Statement
Based on the analysis, the statement that covalent compounds form well-defined lattices is not true. This characteristic is specific to ionic compounds.

**Final Answer:** The statement that covalent compounds form well-defined lattices is not true.