which of the following is not soluble ?
(1)sodium chromate
(2)lead(II)iodide
(3)lithium hydroxide
(4)ammonium sulfate
is it 2, im not sure.
The solubility rules I gave you earlier tells you it is 2. (rule 3). So you should be sure.
You need to memorize these rules. They aren't complete but for a simple set they will get you by 99% of the time.
To determine which compound is not soluble, we need to consider the solubility rules. Solubility refers to the ability of a substance to dissolve in a solvent like water. In general, compounds containing Group 1 (alkali metals) cations and most nitrate, acetate, and ammonium salts are soluble in water. Here is how we can analyze each compound:
1) Sodium chromate: Sodium (Na+) is a Group 1 cation, and chromate (CrO4^2-) is typically soluble. Therefore, sodium chromate is soluble.
2) Lead(II) iodide: Lead (Pb2+) is not a Group 1 cation, and iodide (I-) is a halide. Most halides, including iodide, are soluble, except when they are combined with lead, silver, or mercury(II). Therefore, lead(II) iodide is not soluble.
3) Lithium hydroxide: Lithium (Li+) is a Group 1 cation, and hydroxide (OH-) is typically soluble. Therefore, lithium hydroxide is soluble.
4) Ammonium sulfate: Ammonium (NH4+) is a commonly soluble ion, and sulfate (SO4^2-) is typically soluble as well. Therefore, ammonium sulfate is soluble.
Based on this analysis, the compound that is not soluble is lead(II) iodide, option (2).