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## Homework Statement

The spectator ions in the precipitation equation Pb(NO

_{3})

_{2}+ 2KI --> PbI

_{2}+ 2KNO

_{3}are ________.

## Homework Equations

## The Attempt at a Solution

I've been working through a lot of practice problems for next week's final exam, and I seem to be struggling with this concept.

I know the spectator ions 'do nothing', so I am thinking that means they are the ones that are unchanged. That logic got me through most of them, but not this last one.

Here is what I have been doing to solve them (which I know does not yield the correct answer):

I added the charges:

Pb

^{+2}(NO

_{3}

^{+})

_{2}+ 2K

^{+}I

^{-}--> Pb

^{+2}I

^{-}

_{2}+ 2K

^{+}NO

^{-}

_{3}

and then I note what each one does:

Pb

^{+2}--> Pb

^{+2}

(NO

_{3}

^{+})

_{2}--> NO

^{-}

_{3}

2K

^{+}--> 2K

^{+}

2I

^{-}--> I

^{-}

_{2}

So from that logic I would assume that

Pb

^{+2}and 2K

^{+}

are the spectator ions (because they did not change), which is not an answer choice.

What did I do wrong?