Molten NaCl conduct electricity due to the presence of:

• A. Free molecules
• B. Free ions
• C. Free electrons
• D. Free atoms

Molten sodium chloride (NaCl) conducts electricity primarily because of the presence of:

Correct Answer: B. Free ions

When NaCl is heated until it melts, it breaks down into its constituent ions, sodium (Na⁺) and chloride (Cl^-). These ions are free to move in the molten state, allowing them to carry electric current.

Why Other Options Are Incorrect

• A. Free molecules: In molten NaCl, the compound does not exist as free molecules; it exists as ions.
• C. Free electrons: While metals conduct electricity through free electrons, NaCl is an ionic compound and does not have free electrons in its molten state.
• D. Free atoms: The melting of NaCl does not produce free atoms; it produces ions instead.

Thus, the ability of molten NaCl to conduct electricity is due to the mobility of these free ions.