Alkanes containing even number of carbon atoms possess higher melting points than those containing odd number of carbon atoms.

Answer

**Step-by-Step Solution:**

1. **Understanding Alkanes:**
- Alkanes are saturated hydrocarbons with the general formula CnH2n+2, where n is the number of carbon atoms.
- They can have an even or odd number of carbon atoms.

2. **Symmetry in Molecular Structure:**
- Alkanes with an even number of carbon atoms (e.g., C2, C4, C6) tend to have a symmetrical structure.
- Symmetrical molecules can pack more closely together in a solid state.

3. **Packing Efficiency:**
- The close packing of symmetrical alkanes allows for stronger intermolecular forces (like van der Waals forces) to act between the molecules.
- This results in a higher melting point because more energy is required to overcome these forces.

4. **Unsymmetrical Structures:**
- Alkanes with an odd number of carbon atoms (e.g., C3, C5, C7) are generally less symmetrical.
- The unsymmetrical arrangement leads to less efficient packing in the solid state.

5. **Breaking Intermolecular Forces:**
- Because unsymmetrical alkanes are less tightly packed, the intermolecular forces are weaker.
- This means that less energy is required to break these forces, resulting in a lower melting point.

6. **Conclusion:**
- Therefore, alkanes with an even number of carbon atoms have higher melting points compared to those with an odd number of carbon atoms due to their symmetrical structure and better packing efficiency.