Answer:
Salts of the alkali metals are soluble. (Note: The alkali metals are in group 1.)
e.g. If M = Li, Na or K, then MX, M2X, M3X, etc. are soluble regardless of what X is.
2. Ammonium ( + NH4
) salts are soluble.
e.g. NH4 X, ( NH4
)2X, ( NH4
)3X, etc. are soluble regardless of what X is.
3. Nitrates NO3
-
are soluble.
e.g. MNO3, M(NO3)2, M(NO3)3, etc. are soluble regardless of what M is.
4. Halides i.e. chlorides (Cl-
), bromides (Br-
) and iodides (I-
) are soluble except for the
halides of lead (Pb2+), mercury (Hg+
and 2+ H 2
g ) and silver (Ag+
).
e.g. If X = Cl, Br or I, then MX, MX2, MX3, etc. are soluble unless M = Pb, Hg or Ag.
5. Sulfates ( 2-
SO4
) are soluble except for the sulfates of calcium, strontium, barium, silver
mercury and lead.
e.g. M2SO4, MSO4, M2(SO4)3, etc. are soluble unless M is from group 2 (the alkaline
earths) or M = Pb, Hg or Ag.
6. Carbonates ( 2- CO3
), phosphates ( 3- PO4
) and sulfides (S2-
) are insoluble except for
(i) the carbonates/phosphates/sulfides of the alkalis (because of Rule 1), and
(ii) ammonium carbonate/phosphate/sulfide (because of Rule 2).
7. Hydroxides (OH-
) are insoluble or slightly soluble except for the hydroxides of the
alkalis (because of Rule 1).
Note: The hydroxides of group 2 (the alkaline earth metals) are slightly soluble. Virtually
all other hydroxides are insoluble.
Explanation:
