1. The problem involves understanding the solubility and precipitation of compounds formed by the cations Cu^{2+} and Na^{+} with the anions SO_4^{2-} and OH^{-}. 2. The table shows the products formed when these ions combine: - Cu^{2+} + SO_4^{2-} \rightarrow CuSO_4 (R, aqueous) - Na^{+} + SO_4^{2-} \rightarrow Na_2SO_4 (P, aqueous) - Cu^{2+} + OH^{-} \rightarrow Cu(OH)_2 (P, solid) - Na^{+} + OH^{-} \rightarrow NaOH (R, aqueous) 3. Here, "R" indicates the compound remains dissolved (reactant or soluble), and "P" indicates a precipitate forms (product or insoluble). 4. The key concept is solubility rules: - Most sulfate salts are soluble except those of heavy metals like Cu^{2+} which may form soluble or slightly soluble compounds. - Hydroxides of transition metals like Cu(OH)_2 are generally insoluble and precipitate. - Alkali metal salts like Na_2SO_4 and NaOH are soluble. 5. Therefore, CuSO_4 is soluble (R, aqueous), Na_2SO_4 is soluble (P, aqueous) but marked as product, Cu(OH)_2 precipitates (P, solid), and NaOH is soluble (R, aqueous). This table helps predict which combinations form precipitates and which remain dissolved in aqueous solution.