Which has the highest melting point? CH3OH, CCl4. CH3Cl, KCl, or BCl3
The Correct Answer and Explanation is:
Among the given compounds, KCl has the highest melting point.
Here’s why:
- KCl (Potassium Chloride):
- KCl is an ionic compound composed of K⁺ and Cl⁻ ions. Ionic bonds are generally very strong due to the electrostatic attraction between oppositely charged ions. The strength of these bonds leads to a high melting point because it takes a significant amount of energy to overcome the attraction between the ions.
- CH3OH (Methanol):
- Methanol is a polar molecule that exhibits hydrogen bonding between molecules. While hydrogen bonding is strong, it is still weaker than ionic bonds. Therefore, methanol has a relatively lower melting point compared to ionic compounds like KCl.
- CCl4 (Carbon Tetrachloride):
- CCl4 is a nonpolar molecule with London dispersion forces acting between its molecules. These forces are generally weak, leading to a low melting point for CCl4 compared to polar or ionic compounds.
- CH3Cl (Methyl Chloride):
- Methyl chloride is a polar molecule, and while it has dipole-dipole interactions, these interactions are weaker than ionic bonds. This results in a melting point lower than that of KCl but higher than that of nonpolar molecules like CCl4.
- BCl3 (Boron Trichloride):
- Boron trichloride is a covalent compound with weaker van der Waals forces between molecules. This results in a relatively low melting point, as it lacks strong intermolecular forces like hydrogen bonds or ionic bonds.
Conclusion:
KCl has the highest melting point because it is an ionic compound with very strong electrostatic forces between its ions. In contrast, the other molecules, whether polar or nonpolar, rely on weaker intermolecular forces.
