Question

When lead(l) nitrate reacts with sodium iodide, what is the formula for the product lead (lI) iodide?

Answer 1

`"Lead(II) iodide"` `-=` `PbI_2`

Explanation:

`Pb^(2+) + 2I^(-) rarr PbI_2(s)darr`

`"Lead(II) iodide"` or (more rarely) `"plumbous iodide"` is a water insoluble, fine yellow powder.

In the given reaction, both mass and charge have been conserved. What does this mean?

The reaction of halides with lead nitrate is often a useful way to identify an unknown halide. `PbCl_2` forms an insoluble white precipitate; `PbBr_2` forms an insoluble cream-coloured precipitate; and `PbI_2` forms an insoluble bright yellow precipitate.