The symbol (aq) after a chemical formula indicates the substance is in what state?

The symbol (aq) after a chemical formula indicates the substance is in what state?

• A. (aq)
• B. Gas
• C. Solid
• D. Liquid

Answer: (A)

When you see (aq) after a chemical formula, it means the substance is in an aqueous solution—dissolved in water. The labels gas, solid, and liquid describe the physical state of a pure substance, but (aq) indicates the environment the species is in: water as the solvent, with the solute present as dissolved ions or molecules. This is why reactions are written with species labeled (aq) to show they are in solution rather than in a distinct solid, liquid, or gas phase. For example, dissolved salts produce ions in water, which are represented as aqueous species.

When you see (aq) after a chemical formula, it means the substance is in an aqueous solution—dissolved in water. The labels gas, solid, and liquid describe the physical state of a pure substance, but (aq) indicates the environment the species is in: water as the solvent, with the solute present as dissolved ions or molecules. This is why reactions are written with species labeled (aq) to show they are in solution rather than in a distinct solid, liquid, or gas phase. For example, dissolved salts produce ions in water, which are represented as aqueous species.