Question

Question #3d2dd

Answer 1

You get a precipitate of iron(III) hydroxide, `Fe(OH)_3(s)`.

Explanation:

The net equation is:

`OH^"-"(aq) + Fe^"3+"(aq) -> Fe(OH)_3(s)`

This double displacement reaction is driven by the very low solubility of iron(III) hydroxide (`5.3*10^"-5" "g"//"100 g of water"`) at 20 °C).

`3KOH(aq) + Fe(NO_3)_3(aq) -> Fe(OH)_3(s) + 3KNO_3(aq)`

Potassium (`K^"+"(aq)`) and nitrate (`NO_3^"-"(aq)`) are spectator (unchanged) ions.

Filter out the iron(III) hydroxide precipitate and you'll have a solution of pure potassium nitrate, `KNO_3(aq)`.

After evaporation of water, if there isn't any excess of iron(III) or hydroxide, we can eventually crystallise a solid sample of the second product: `KNO_3`.