Aqueous Solution: Definition and Properties


Aqueous Solution: Definition and Properties

An aqueous solution is a mixture of two or more substances, where one substance is dissolved in water. Water is known as the universal solvent because it can dissolve a wide range of materials. This is due to its unique structure and polarity, making it an excellent medium for chemical reactions to take place.


By definition, an aqueous solution contains water as the solvent and a solute, which is the substance that is dissolved in the water. The solute can be a solid, liquid, or gas, and it is evenly distributed throughout the solution.


1. Conductivity: Aqueous solutions have the ability to conduct electricity. This is due to the presence of ions in the solution. When a substance dissolves in water, it breaks down into its constituent ions, which are positively or negatively charged. These ions allow for the flow of electricity, making aqueous solutions conductive.

2. pH: Aqueous solutions have a pH value, which is a measure of the acidity or basicity of the solution. Water has a neutral pH of 7, but when a solute is added, it can change the pH of the solution. For example, adding an acidic substance will decrease the pH, making the solution more acidic, while adding a basic substance will increase the pH, making the solution more basic.

3. Solubility: The solubility of a substance in water refers to its ability to dissolve in the solvent. Some substances are highly soluble in water, while others are insoluble. The solubility of a substance in water depends on various factors such as the structure of the substance, temperature, and pressure.

4. Density: The density of an aqueous solution is affected by the amount of solute dissolved in the solution. Generally, adding a solute to water will increase the density of the solution. However, in some cases, the solute may decrease the density, depending on its molecular weight and its attraction to water molecules.

5. Boiling and Freezing Point: Adding a solute to water will change its boiling and freezing points. This is due to the change in the water’s properties caused by the presence of the solute. For example, adding salt to water will increase its boiling point, making it take longer to boil, and decrease its freezing point, making it freeze at a lower temperature.


Aqueous solutions play a vital role in various industries and everyday life. Some common applications of aqueous solutions include:

1. Pharmaceutical Industry: Aqueous solutions are commonly used in the pharmaceutical industry to create medicines. Many drugs are made by dissolving active ingredients in water, which makes them easier to consume and more effective.

2. Food and Beverage Industry: Aqueous solutions are used in the production of many food and beverage products. For example, sugar is dissolved in water to make a simple syrup, and soda is a carbonated aqueous solution.

3. Cleaning Products: Many household and industrial cleaning products, such as detergents and soaps, are made using aqueous solutions. Water helps to dissolve and distribute the active cleaning agents, making them more effective.

4. Agriculture: Aqueous solutions are used in agriculture to mix and deliver fertilizers and pesticides to crops. These solutions are also used to water plants, providing them with essential nutrients.

In conclusion, aqueous solutions are an essential part of our daily lives and various industries. Their unique properties make them a versatile medium for various processes and applications. Understanding the properties and behavior of aqueous solutions is crucial in fields such as chemistry, biology, and environmental science, where these solutions play a significant role.