Which of the following are considered insoluble?
PbI2
NaNO3
Na2S
Mg(OH)2
NH4OH
AgCl
Here are the solubility rules. You need to know them.
https://www.chemteam.info/Solutions/Solubility-Rules.html
To determine which of the following compounds are considered insoluble, we need to refer to a solubility table or solubility rules. These rules provide guidelines on which compounds are generally soluble or insoluble in water.
Here are the solubility rules for your reference:
1. All common sodium, potassium, and ammonium salts are soluble.
2. All nitrates (NO3-) and acetates (C2H3O2-) are soluble.
3. Most chlorides (Cl-), bromides (Br-), and iodides (I-) are soluble, except for those of silver, lead, and mercury (I and II).
4. Most sulfates (SO4^2-) are soluble, except for those of lead, barium, and calcium.
5. Most hydroxides (OH-) are insoluble, except for those of sodium, potassium, and calcium.
6. Most sulfides (S^2-) are insoluble, except for those of sodium, potassium, and calcium.
Now, let's determine the solubility for each compound:
PbI2: According to rule 3, most iodides are soluble except for those of silver, lead, and mercury (I and II). Therefore, PbI2 is insoluble.
NaNO3: According to rule 2, nitrates are soluble. Therefore, NaNO3 is soluble.
Na2S: According to rule 6, sulfides are insoluble, except for those of sodium, potassium, and calcium. Therefore, Na2S is soluble.
Mg(OH)2: According to rule 5, hydroxides are insoluble, except for those of sodium, potassium, and calcium. Therefore, Mg(OH)2 is insoluble.
NH4OH: According to rule 5, hydroxides are insoluble, except for those of sodium, potassium, and calcium. Therefore, NH4OH is insoluble.
AgCl: According to rule 3, most chlorides are soluble except for those of silver, lead, and mercury (I and II). Therefore, AgCl is insoluble.
In summary, the compounds that are considered insoluble are PbI2, Mg(OH)2, NH4OH, and AgCl.