As an expert in the field of chemistry, I can provide you with a detailed explanation regarding the electrical conductivity of salt, specifically sodium chloride (NaCl), in its solid state.

Sodium chloride, commonly known as table salt, is an ionic compound composed of positively charged sodium ions (Na+) and negatively charged chloride ions (Cl-). The structure of solid sodium chloride is a crystalline lattice where each sodium ion is surrounded by six chloride ions, and vice versa, in a three-dimensional arrangement. This arrangement is due to the electrostatic attraction between the oppositely charged ions, which forms what is known as an ionic bond.

In its solid state, sodium chloride is not a good conductor of electricity. This is because the ions are held in fixed positions within the crystal lattice and are not free to move. Electrical conductivity occurs when charged particles, such as electrons or ions, can move freely through a material. Since the ions in solid sodium chloride are immobile, they cannot carry an electric current.

However, when sodium chloride is dissolved in water or when it is molten, it becomes an excellent conductor of electricity. This change in behavior is due to the disruption of the ionic lattice. When NaCl dissolves in water, the polar water molecules surround the Na+ and Cl- ions, breaking the ionic bonds and allowing the ions to move freely within the solution. This process is known as hydration. The free movement of these ions in the solution enables them to carry an electric current, making the solution conductive.

The melting point of sodium chloride is around 801°C (1,474°F), which is significantly lower than the melting point of magnesium oxide (MgO), which is approximately 2,800°C. The difference in melting points can be attributed to the strength of the ionic bonds. In magnesium oxide, the Mg2+ ions and O2- ions carry a greater number of charges compared to the Na+ and Cl- ions in sodium chloride. The stronger the charge on the ions, the stronger the electrostatic attraction between them, resulting in stronger ionic bonds and a higher melting point.

In summary, solid sodium chloride does not conduct electricity because its ions are held in a fixed lattice structure and cannot move freely. However, when dissolved in water or in a molten state, the ionic bonds are broken, and the ions are free to move, allowing the substance to conduct electricity. The difference in melting points between sodium chloride and magnesium oxide is due to the greater number of charges on the ions in magnesium oxide, leading to stronger ionic bonds and a higher melting point.

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Non-conductive in its solid state, but when dissolved in water or molten NaCl will conduct electricity. Higher melting point than sodium chloride: around 2,800oC. This is because its Mg2+ and O2- ions have a greater number of charges, so they form stronger ionic bonds than the Na+ and Cl- ions in sodium chloride.read more >>