Question

which of the following is insoluble in water? cu(ch3coo)2 cucl2 cuso4 cu(no3)2 cu(oh)2

Explanation:

Step1: Recall solubility rules

Salts of acetate ($\text{CH}_3\text{COO}^-$), chloride ($\text{Cl}^-$), sulfate ($\text{SO}_4^{2-}$), and nitrate ($\text{NO}_3^-$) are generally soluble. Hydroxides ($\text{OH}^-$) are generally insoluble except for Group 1 and some Group 2 metals.

Step2: Analyze each compound

• $\text{Cu(CH}_3\text{COO)}_2$: Acetate salt, soluble.
• $\text{CuCl}_2$: Chloride salt, soluble.
• $\text{CuSO}_4$: Sulfate salt, soluble.
• $\text{Cu(NO}_3)_2$: Nitrate salt, soluble.
• $\text{Cu(OH)}_2$: Hydroxide of copper (not Group 1 or Group 2), insoluble.

Answer:

$\text{Cu(OH)}_2$