Read the given passage and answer the questions.
The physical states of the reactants and products can be represented by using the symbols (s) for solids, (l) for liquids, (g) for gases and (aq) for aqueous solution along with their respective formulae. The word aqueous is written if the reactant or product is present as a solution in water. Precipitate can also be represented by using an arrow pointing downwards `(darr)` instead of using symbol (s).
In the same way, the gaseous state of an evolved gas can be represented by using an arrow pointing upward direction `(uarr)` instead of using symbol (g). The specific condition of the reaction like temperature, pressure, catalyst etc. is written above or below the arrow in the chemical equation.
If the reactant or product is present as a solution of water , it is represented as:

Options

A. (s)
B. (l)
C. (aq)
D. `darr`

Explanation

To answer the question about how to represent reactants and products that are present as a solution in water, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding the Context**: The question asks how to represent reactants and products that are in an aqueous solution when writing a chemical equation.

2. **Identifying the Representation**: In chemical equations, different physical states of matter are represented by specific symbols.
- Solids are represented by (s)
- Liquids are represented by (l)
- Gases are represented by (g)
- Aqueous solutions (substances dissolved in water) are represented by (aq).

3. **Applying the Knowledge**: Since the question specifically asks about substances that are in a solution in water, we need to focus on the aqueous state.

4. **Conclusion**: Therefore, when a reactant or product is present as a solution in water, it is represented by the symbol (aq).

### Final Answer:
If the reactant or product is present as a solution in water, it is represented as (aq).

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