Hydrosol is a colloidal suspension, which is a heterogeneous mixture consisting of two phases: the dispersed phase and the dispersion medium. In the case of hydrosols, the dispersed phase is typically solid particles, and the dispersion medium is water. Let’s explore each option in detail to explain why option C (solid and water) is the correct answer, while the other options are not.

Option A:

Gas and Water This option is incorrect because hydrosols are not composed of a gaseous dispersed phase and water as the dispersion medium. Hydrosols involve solid particles suspended in water, not gas. Gases, unlike solids, are highly compressible and tend to disperse readily in any available space. Therefore, gas is not an appropriate candidate for the dispersed phase in hydrosols.

Option B:

Liquid and Water This option is also incorrect because hydrosols do not typically involve a liquid dispersed phase and water as the dispersion medium. Hydrosols are defined by the presence of solid particles dispersed in water, not a liquid phase. Liquid-liquid suspensions have different names, such as emulsions (for immiscible liquids) or solutions (for miscible liquids).

Option D:

Water and Solid Option D is not correct because it presents the same components as option C, but in reverse order. The dispersed phase in hydrosols is solid, and the dispersion medium is water. In option D, it suggests the opposite arrangement, which is not consistent with the definition of hydrosols. Therefore, option D is incorrect.

Now, let’s provide more detailed information about why option C is the correct answer:

Option C:

Solid and Water Hydrosols, as mentioned earlier, consist of solid particles as the dispersed phase and water as the dispersion medium. This arrangement is characteristic of hydrosols and is consistent with the definition of colloidal systems. Solid particles in hydrosols can be various substances, such as metal nanoparticles, organic compounds, or minerals, suspended within water.

These solid particles are typically much larger than individual molecules or ions but small enough to remain suspended in the water without settling due to gravity. The water molecules surround and stabilize the solid particles, preventing them from clumping together and maintaining a stable colloidal suspension.

Hydrosols have a wide range of applications, including in cosmetics, pharmaceuticals, food and beverages, and various industrial processes. They are valued for their ability to disperse active solid ingredients evenly and provide unique properties to products.

For instance, silver hydrosol is used for its antibacterial properties in some medical applications, while colloidal silica hydrosols are used in the production of semiconductor wafers for the electronics industry.

In summary, hydrosols are colloidal systems where solid particles are dispersed in water as the dispersion medium. This arrangement distinguishes them from other types of colloidal systems, such as aerosols (gas dispersed in a liquid or solid) or emulsions (liquid dispersed in a liquid). Option C correctly identifies the components of a hydrosol, making it the correct answer.

To further illustrate the importance of understanding the components of colloidal systems, let’s briefly explore the characteristics of other types of colloids:

Aerosols (Option A):

Aerosols consist of a gas dispersed in a liquid or solid. Common examples include fog (liquid droplets in air) and smoke (solid particles in air). Aerosols play a crucial role in atmospheric science, climate modeling, and various industrial processes. They differ from hydrosols in that the dispersed phase is gaseous, not solid.

Emulsions (Option B):

Emulsions involve the dispersion of one immiscible liquid within another, such as oil dispersed in water or vice versa. Examples include mayonnaise (oil in water) and butter (water in oil). Emulsions are essential in the food industry, cosmetics, and pharmaceuticals. The dispersed phase in emulsions is liquid, contrasting with hydrosols where it is solid.

Suspensions (Option D):

Suspensions consist of solid particles dispersed in a liquid or solid medium. Examples include muddy water (solid particles in water) and chalk in water (solid particles in a liquid).

While suspensions share similarities with hydrosols in terms of having a solid dispersed phase, suspensions can also involve solid particles in a solid medium, as seen in the example of chalk in water. However, suspensions differ from hydrosols in terms of the dispersion medium, which can be either liquid or solid.

In conclusion, understanding the components of colloidal systems is essential in various fields, including chemistry, materials science, and industry. The correct answer to the question regarding hydrosols is option C, as hydrosols consist of a solid dispersed phase and water as the dispersion medium.

Options A, B, and D are incorrect because they do not align with the specific characteristics of hydrosols. Each of these options describes different types of colloidal systems with distinct dispersed phase and dispersion medium arrangements, such as aerosols, emulsions, and suspensions, respectively.