Question #3d2dd

1 Answer

You get a precipitate of iron(III) hydroxide, Fe(OH)3(s).

Explanation:

The net equation is:

OH-(aq)+Fe3+(aq)Fe(OH)3(s)

This double displacement reaction is driven by the very low solubility of iron(III) hydroxide (5.310-5g/100 g of water) at 20 °C).

3KOH(aq)+Fe(NO3)3(aq)Fe(OH)3(s)+3KNO3(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, KNO3(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: KNO3.