CHEMISTRY · Single correct · A Level · Chemistry · Bonding · Bonding
Problem
A white crystalline solid, X, melts at 801 °C and conducts electricity only when molten or dissolved in water. Elemental analysis shows that X contains sodium and chlorine in a 1 : 1 atomic ratio. Which classification of X is most consistent with these data?
(a) Network-covalent solid, because the very high melting point shows covalent bonds extending throughout the crystal
(b) Metallic solid, because its ability to conduct electricity implies mobile electrons moving through the lattice
(c) Ionic compound, because strong electrostatic forces between Na+ and Cl− give a high melting point and permit conductivity only when the ions are mobile (molten or in solution)
(d) Molecular compound, because the 1 : 1 atomic ratio indicates simple NaCl molecules held together by intermolecular forces