What is the correct formula unit for the ionic compound, lead(II) iodide?

? PbI
? PbI2
? Pb2I
? PbI4
? Pb2I2

1 answer

The correct formula unit for the ionic compound lead(II) iodide is PbI2.

In this compound, lead has a +2 charge (as indicated by "lead(II)"), and iodine has a -1 charge. To balance the charges, two iodide ions are needed for each lead ion, resulting in the formula PbI2.