The ionic compound, manganese(II) iodide, is composed of which of the following pairs of ions?

Question

? 1 Mg2+ ion and 2 I- ions
? 1 Mn- ion and 1 I- ion
? 1 Mn2+ ion and 2 I- ions
? 1 Mn2+ ion and 1 I2- ion
? 1 Mn+ ion and 1 I- ion

Answer 1

Manganese(II) iodide is composed of manganese ions with a +2 charge and iodide ions with a -1 charge. Therefore, the correct ion pair would be:

? 1 Mn²⁺ ion and 2 I⁻ ions

This reflects that two iodide ions are needed to balance the charge of one manganese(II) ion.