The word aqueous (aq) is written if the reactant or product is present as a/an-

Correct option is B

The correct answer is (b) Solution in water.
· The term aqueous (aq) is used in chemical equations to denote that a substance is dissolved in water. An aqueous solution means that water is the solvent, and the substance (reactant or product) is dissolved in it.
Information Booster:
· Concentrated solution: Refers to a solution with a high amount of solute relative to the solvent but does not specifically refer to water.
· Isotonic solution: Refers to a solution with equal osmotic pressure compared to another solution, often used in biological contexts.
· Solution in kerosene: Refers to a non-aqueous solution, where kerosene is the solvent, not water.