The movement of colloidal particle under the influence of electric field is called: (a) Electro dialysis (b) Electro osmosis (c) Electrolysis (d) Electrophoresis

Colloidal particles are tiny particles that exist in a state of matter known as a colloid. A colloidal system consists of dispersed particles—usually solid or liquid—that are spread throughout a continuous medium, which is also generally solid or liquid. Imagine a mist of fine spray: the droplets of water in the air are acting as colloidal particles in a gaseous medium.

Colloids have interesting properties; notably, the particles are large enough to scatter light but too small to settle out of the solution due to gravity. This scattering of light is called the Tyndall effect and is one reason why colloidal solutions can appear cloudy or have a slight color. Colloidal particles bear an electric charge which can be either positive or negative. This charge is crucial in many applications and behaviors of colloids, particularly in the process of moving under the influence of an electric field—this is what leads us to the concept of electrophoresis.

An electric field in chemistry represents the force field that surrounds a charged particle, such as an ion, electron, or colloid. Think of it as an invisible energy that can push or pull charged particles in different directions depending on the nature of their charge. In the context of chemistry, the electric field is used to induce motion or cause a chemical change.

• An electric field can drive the migration of ions during reactions involving electrolytes.
• It's pivotal in techniques like electrophoresis, where it's used to separate charged molecules.
• Electric fields can alter the speed of reaction by lowering the activation energy required, therefore changing the rate at which reactions occur.

The direction and strength of an electric field are key factors in influencing how charged particles will behave when they are subjected to this field. In a uniform electric field, for example, charged colloidal particles will move in a straight line, toward the electrode with the charge opposite to their own.

In chemistry, separation techniques are fundamental for isolating components of mixtures and are critical in both analytical and preparative contexts. Chemical separation is essential for purification, analysis, and studying the various components of a mixture. There are several methods used for chemical separation, including:

Distillation

Distillation involves heating a liquid to create vapor, which is then condensed back into liquid and collected. This technique relies on differences in boiling points to separate components.

Filtration

Filtration is the process of separating solids from fluids (liquids or gases) by adding a medium through which only the fluid can pass.

Chromatography

Chromatography separates substances based on differences in their movement through a stationary medium, with various forms including paper, liquid, and gas chromatography.

Electrophoresis

A particularly relevant method is electrophoresis, which utilizes an electric field to move charged particles through a medium, such as a gel, allowing them to be separated based on size and charge. This technique is highly effective for separating proteins, DNA, or RNA fragments for research and diagnostic purposes. Its preciseness makes it an invaluable tool in the arsenal of modern chemical analysis and biochemistry.