Which would you expect to have a higher melting point: sodium chloride,NaCl,or aluminum oxide, AL₂O₃? A)The aluminum oxide has a higher melting point because it is a larger molecule and has a greater number of molecular interactions. B)NaCl has a higher melting point because it is a solid at room temperature. C)The aluminum oxide has a higher melting point because of the greater charges of the ions,and hence the greater force of attractions between them. D)The aluminum oxide has a higher melting point because of the covalent bonds within the molecule.

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Aluminum oxide has a higher melting point because of the greater charges of the ions (3+ and 2-) and hence the greater force of attractions between them. NaCl has lower charges (1+ and 1-), resulting in weaker attractive forces between the ions. The size of the molecules (choice A) or the physical state at room temperature (choice B) are not significant factors in determining melting point, and covalent bonds are not present in ionic compounds like NaCl and Al2O3 (choice D is incorrect).

Which Would You Expect to Have a Higher Melting Point