Final answer:
To write the chemical formula for a binary ionic compound, one must balance the metal ion with the nonmetal ion to achieve neutrality. For example, aluminum nitride is written as AlN. Ionic compounds conduct electricity when dissolved, have high melting points, and are water-soluble.
Step-by-step explanation:
When writing the chemical formula for binary ionic compounds, you begin with the metal ion and its charge, and then write the nonmetal ion with its charge. To ensure that the compound is electrically neutral, you need to balance the positive and negative charges. For example, to write the formula of aluminum nitride, use the ions aluminum (Al3+) and nitride (N3-) in a 1:1 ratio to get AlN because the charges cancel each other out. Ionic compounds exhibit distinct characteristics, such as conducting electricity when molten or in a solution but not in the solid state, and having high melting points due to the strong ionic bonds.
Here are formulas for given ionic compounds:
- chromium(III) phosphide - CrP
- mercury(II) sulfide - HgS
- manganese(II) phosphate - Mn3(PO4)2
- copper(I) oxide - Cu2O
- iron (III) chloride dihydrate - FeCl3·2H2O
Molecular compounds generally have lower melting points than ionic compounds. Ionic compounds do not conduct electricity in their solid forms but can conduct when melted or dissolved in water. Substances that are generally water-soluble include ionic compounds and polar molecular compounds. Moreover, ionic compounds are brittle and have high melting points due to the strong attractions between the ions. When an electric current is passed through a solution of an ionic compound, it dissociates into its constituent ions, which conduct electricity.