Which of the following aqueous solutions

should form a precipitate with aqueous
Fe(NO3)3?
1. KOH
2. KCl
3. K2SO4
4. KNO3

Fe(OH)3 is insoluble in water.

well DrBob222 that answers the question in no way its one of those 4 answers

and the answer is KOH

Well Kae,

3KOH + Fe(NO3)3 -> 3KNO3 + Fe(OH)3

To determine which of the aqueous solutions should form a precipitate with aqueous Fe(NO3)3, we need to identify the combination that will result in the formation of an insoluble compound.

In this case, Fe(NO3)3 is a salt of iron (III) and nitrate ions. We need to consider the solubility rules to determine which of the solutions will form a precipitate.

Solubility rules state that most salts containing alkali metal cations (such as K+) and nitrate (NO3-) ions are soluble in water and do not form precipitates.

1. KOH: This is potassium hydroxide, an alkali metal hydroxide. Hydroxide compounds are usually insoluble except when combined with alkali metals such as K+. Therefore, this combination is likely to form a precipitate with Fe(NO3)3. The equation for the reaction is:
Fe(NO3)3 + 3KOH → Fe(OH)3(s) + 3KNO3

2. KCl: This is potassium chloride, a salt commonly found to be soluble in water. Therefore, it will not form a precipitate with Fe(NO3)3.

3. K2SO4: This is potassium sulfate, another common salt that is soluble in water. Therefore, it will also not form a precipitate with Fe(NO3)3.

4. KNO3: This is potassium nitrate, a nitrate salt. As mentioned earlier, nitrate salts are typically soluble in water and do not form precipitates. So, it will not form a precipitate with Fe(NO3)3.

Based on the solubility rules, the only solution that will form a precipitate with aqueous Fe(NO3)3 is KOH (Option 1).