Based on general solubility rules, which of the following salts would dissolve most completely in water at room temperature, and what would the solution look like after dissolution?

• A. NaCl; the solution would be clear with no visible solid remaining.
• B. CaCO3; the solution would be cloudy with undissolved solid present.
• C. AgCl; the solution would be cloudy with undissolved solid present.
• D. PbSO4; the solution would be cloudy with undissolved solid present.

Answer: (A)

Verified step by step guidance

1. Recall the general solubility rules for ionic compounds in water: most alkali metal salts (like Na+) and nitrates are soluble, while many salts containing carbonate (CO\_3^{2-}), chloride (Cl^-), sulfate (SO\_4^{2-}), and other anions may be insoluble or sparingly soluble depending on the cation.
2. Identify the cations and anions in each salt: NaCl (sodium chloride), CaCO\_3 (calcium carbonate), AgCl (silver chloride), and PbSO\_4 (lead sulfate).
3. Apply the solubility rules: NaCl is generally very soluble in water because sodium salts are soluble; CaCO\_3, AgCl, and PbSO\_4 are known to be sparingly soluble or insoluble, meaning they do not dissolve completely and leave some solid undissolved.
4. Predict the appearance of the solution after dissolution: a completely dissolved salt like NaCl will produce a clear solution with no visible solid, while sparingly soluble salts like CaCO\_3, AgCl, and PbSO\_4 will result in a cloudy solution due to undissolved solid particles.
5. Conclude that NaCl dissolves most completely in water at room temperature, resulting in a clear solution, whereas the other salts remain partially undissolved and cause cloudiness.