IONIC COMPOUNDS

IONIC COMPOUND

FORMULA UNIT FOR AN IONIC COMPOUND

• The lowest whole-number ratio of ions in an ionic compound.
• Sodium Chloride- the lowest whole number ratio of the ions 1:1 (One NA+ to each Cl-)
• Formula unit for sodium chloride: NaCl.
• Although Ionic charges are used to derive the correct formula,
• they are not shown when you write the formula

MgCl2

• Magnesium cations (Mg2+) Chloride anions (Cl-)
• Ratio of magnesium cations to chloride anions is 1:2 (one Mg2+ to two Cl-)
• Formula unit: MgCl2- there are twice as many chloride anions as magnesium
• cations, the compound is electrically neutral.
• Chloride anions (each with 1- charge) magnesium cations(each with 2+ charge)

WHAT PROPERTIES CHARACTERIZE IONIC COMPOUNDS?

• Crystalline solids at room temp
• Generally have high melting points
• Conduct an electrical current when melted

WHATS THE CHEMICAL FORMULA FOR K+,S2-