Question

Question #bb7b1

Answer 1

To predict which ionic compounds are insoluble in water you use “solubility rules” to first eliminate the soluble possibilities.

Explanation:

You go down the solubility rules in order and stop at the first rule that applies.

SOLUBILITY RULES

1. All common compounds of `"NH"_4^+` and the Group 1 elements are soluble.

2. `"NO"_3^"-", "ClO"_3^"-", "ClO"_4^"-", "C"_2"H"_3"O"_2^"-"` — all common nitrates, chlorates, perchlorates, and acetates are soluble.

3. `"F"^"-", "Cl"^"-", "Br"^"-", "I"^"-"` — all halides are soluble EXCEPT those of `"Ag"^+, "Hg"_2^"2+", "Pb"^"2+"` and the fluorides of `"Mg"^"2+", "Ca"^"2+", "Sr"^"2+"`, and`"Ba"^"2+"`.

4. `"SO"_4^"2-"` — most sulfates are soluble EXCEPT those of `"Sr"^"2+", "Ba"^"2+", "Ca"^"2+", "Pb"^"2+"`, `"Hg"_2^"2+"`, and `"Hg"^"2+"`.

5. `"CO"_3^"2-", "C"_2"O"_4^"2-", "OH"^"-", "O"^"2-", "SO"_3^"2-", "PO"_4^"3-", "CrO"_4^"2-", "S"^"2-"` — all carbonates, oxalates, hydroxides, oxides, phosphates, chromates, and sulfides are insoluble.

EXAMPLES

Classify these compounds as soluble or insoluble in water:

tin(II) sulfate — soluble (Rule 4)

lead(II) chromate — insoluble (Rule 5)

ammonium sulfide — soluble (Rule 1)

strontium chlorate — soluble (Rule 2)

silver bromide — insoluble (Rule 3)

sodium phosphate — soluble (Rule 1)

copper(I) carbonate — insoluble (Rule 5)

barium sulfate — insoluble (Rule 4)