Glendale Community College
Solubilities of Ionic Compounds
Chemistry 130 Spring Session 2012
Page 1 of 2
Solubilities of Ionic Compounds in One Lesson
A review by W.H. Wingo
The following flow chart illustrates the solubilities of common ionic compounds in water. It contains the
same information as table 7.3, p 200 in Tro, Introductory Chemistry, 2nd edition, and is similar but not quite
identical to the GCC CHM 130 “Periodic Table information.” For instructions on use of the chart, see page 2.
START
NH4+, Li+,
Na+, K+
yes
SOLUBLE
no
C2H3O2−, NO3−
yes
no
Cl−, Br−, I−
no
yes
Ag+, Hg2+,
Pb2+
yes
no
SO42−
yes
yes
Ca2+, Sr2+,
Pb2+, Ba2+
no
PO43−, CO32−
no
yes
no
OH−
INSOLUBLE
INSOLUBLE
SOLUBLE
no
yes
Ca2+, Sr2+,
Ba2+
yes
“Slightly Soluble” *
no
yes
S2−
no
Not Covered Here
Ca2+, Sr2+,
Ba2+
yes
SOLUBLE
no
INSOLUBLE
* Tro states that “for many
purposes” these hydroxides
can be considered insoluble.
Glendale Community College
Solubilities of Ionic Compounds
Chemistry 130 Spring Session 2012
Page 2 of 2
Use of the Flow Chart
First we identify the correct formula of the ionic compound whose solubility is to be determined. Thus, if we
are given “iron (II) sulfate,” we would first have to express it as FeSO4.
Then we enter the chart at the START box and work our way down the left-hand column until we
encounter an ion that is in our formula. For FeSO4, our first “yes” answer comes at sulfate, four boxes down.
(Iron is not listed anywhere in the chart.) The “yes” answer for sulfate takes us to the decision box at the far
right of the same line, and we must check our formula for calcium, strontium, lead (II), and barium ions. Since
iron (II) is not listed, our answer here is “no,” which leads to the SOLUBLE outcome immediately below: iron
(II) sulfate is soluble.
Another example: Lithium carbonate is soluble because it contains lithium ion; however, any carbonate with
a positive ion not listed in the first decision box, such as calcium carbonate or copper (II) carbonate, would give
“no” answers until the fifth decision box down on the left. Here we learn that any carbonate not eliminated in
the first decision box is INSOLUBLE.
Exercises:
Using the flow chart, classify each of the following ionic compounds as soluble or insoluble in water.
1. copper (I) chloride
_______________________________
2. germanium nitrate
_______________________________
3. sodium azide
_______________________________
4. potassium metabisulfate
_______________________________
5. lead (II) acetate
_______________________________
6. any transition metal sulfide
_______________________________
7. francium astatide (very rare….)
_______________________________
8. mercury (II) bromide
_______________________________
9. any transition metal sulfate
_______________________________
10. any column 2 phosphate
_______________________________
11. any transition metal hydroxide
_______________________________
12. tin (II) bromide
_______________________________
13. silver fluoride
_______________________________
14. lead (IV) acetate
_______________________________
15. potassium thiosulfate
_______________________________
16. barium sulfide
_______________________________
17. barium hydroxide
_______________________________
18. calcium nitrate
_______________________________
19. lead (IV) iodide
_______________________________
20. tin (II) phosphate
_______________________________
21. arsenic trioxide
_______________________________
22. rubidium sulfate
_______________________________
23. aluminum chloride
_______________________________
24. hafnium bromide
_______________________________
25. pandemonium iodide (very rare….)
_______________________________