Final answer:
NaCl, an ionic compound, has a higher melting point than LiCl due to its strong ionic bonds and crystal lattice structure. Although listed among covalent compounds, NaCl is the correct answer, as the actual covalent compounds provided have lower melting points due to weaker intermolecular forces.
Step-by-step explanation:
The student has asked which covalent compound has a higher melting point than LiCl. Among the given options H₂O, NaCl, CH₄, and NH₃, NaCl is actually an ionic compound and not a covalent one. As a result, NaCl has a significantly high melting point due to its strong ionic bonds and 3D crystal lattice structure, which is higher than the melting point of LiCl. It's worth noting that H₂O, CH₄, and NH₃ are all covalent compounds with lower melting points than LiCl, primarily due to weaker intermolecular forces compared to the ionic bonding in NaCl.
CH₄ (methane) and NH₃ (ammonia) demonstrate London dispersion forces and hydrogen bonding respectively, but they are not as strong as ionic bonds, leading to their lower melting points relative to LiCl and NaCl.
Therefore, the answer is NaCl, which, despite being listed, is not a covalent compound but stands as the one with a higher melting point than LiCl, due to its ionic nature and the strong electrostatic interactions between Na+ and Cl- ions.