Comment on the statement that ‘Colloid is not a substance but a state of substance.

The statement that "colloid is not a substance but a state of substance" is a concise and accurate way to describe colloids in the context of chemistry. Colloids are indeed not a distinct substance but rather a specific state or phase of matter that certain substances can exist in. To understand this statement better, let's break it down:

Colloids: Colloids are a type of heterogeneous mixture where tiny particles of one substance are dispersed throughout another substance. The particles in a colloid are larger than individual molecules or ions but smaller than the particles in a suspension. Common examples of colloids include milk, mayonnaise, and fog.

Not a Substance: A substance in chemistry typically refers to a pure chemical compound with a specific chemical formula and properties. Colloids do not fit this definition because they are not a pure substance. Instead, they are a mixture of at least two substances: one that is dispersed as small particles (the dispersed phase) and another in which these particles are dispersed (the continuous phase).

State of Substance: Colloids represent a specific state or phase that certain substances can adopt under particular conditions. The formation of a colloid depends on factors like the size and nature of the particles, the dispersing medium, and environmental conditions such as temperature and pressure. Therefore, colloids are not unique substances themselves but rather a way that substances can arrange themselves within a mixture.

In summary, the statement is a useful way to emphasize that colloids are not distinct substances but rather a particular arrangement or state that substances can assume when dispersed in a medium. Understanding colloids in this context is essential in chemistry and has practical applications in various industries, including food science, pharmaceuticals, and materials science.