Use the solubility rules to decide which of the following compounds are soluble in water:
barium sulfate
copper(II) carbonate
Ni(OH)2
Ca(NO3)2
FeCl2
silver nitrate
To determine the solubility of compounds in water, we can use a set of solubility rules. These rules provide guidelines for predicting whether a compound will dissolve or remain insoluble in water.
1. Rule 1: All nitrates (NO3-) are soluble.
Using Rule 1, we can conclude that Ca(NO3)2 (calcium nitrate) and silver nitrate (AgNO3) are both soluble in water.
2. Rule 2: Most hydroxides (OH-) are insoluble, but hydroxides of alkali metals (Group 1) and ammonium (NH4+) are soluble.
According to Rule 2, Ni(OH)2 (nickel hydroxide) is insoluble in water because nickel is not an alkali metal or ammonium.
3. Rule 3: Most chlorides (Cl-) are soluble, except those of silver (Ag+), lead (Pb2+), and mercury (Hg2+).
Applying Rule 3, we find that barium sulfate (BaSO4) is insoluble in water because barium is not one of the exceptions mentioned. Similarly, FeCl2 (iron (II) chloride) is soluble in water because iron (II) is not one of the exceptions.
4. Rule 4: Carbonates (CO3-), phosphates (PO4-3), sulfides (S2-), and sulfates (SO4-2) are insoluble, except those of alkali metals and ammonium.
Based on Rule 4, we can determine that copper(II) carbonate (CuCO3) is insoluble in water.
In summary, the solubility of the given compounds in water is as follows:
Soluble in water: Ca(NO3)2, silver nitrate, FeCl2
Insoluble in water: barium sulfate, copper(II) carbonate, Ni(OH)2