Problem 38 - A Complete Resource Book in Chemistry for JEE Main

Question

The process of separating a crystalloid, from a colloid by filtration, is called (a) emulsification (b) dialysis (c) coagulation (d) peptization

Step-by-Step Solution

Answer

(b) dialysis

Step 1: Identify Key Concepts

The question involves understanding the process of separating crystalloid from colloid by filtration. Clarify what crystalloids, colloids, and filtration are. Crystalloids are substances that can be dissolved and pass through a semi-permeable membrane, while colloids have larger particles that cannot.

Step 2: Understand the Process

Learn about the filtration process used to separate crystalloids and colloids. In this context, the specific method that separates these substances by allowing smaller crystalloid particles to pass through while retaining larger colloid particles is important.

Step 3: Match the Term

Review the terms provided in the options: (a) emulsification, (b) dialysis, (c) coagulation, and (d) peptization. Determine which term is associated with the separation of crystalloids and colloids by filtration.

Step 4: Apply the Knowledge

Among the options, dialysis is the process that fits the filtration method of separating crystalloids from colloids. Dialysis allows small molecules to pass through a semi-permeable membrane, retaining larger particles.

Key Concepts

Crystalloids

Crystalloids are substances that have the capability to dissolve in a solvent and create a true solution. In scientific terms, they are capable of passing through a semi-permeable membrane due to their small particle size. This makes them particularly distinct and useful in processes of separation and medical treatments such as dialysis.

Common characteristics of crystalloids include:

• They form homogenous mixtures when dissolved in liquids like water.
• Their small particles enable them to pass easily through semi-permeable membranes.
• Often used in medical treatments for replenishing fluids in the body, such as saline and dextrose solutions.

Understanding crystalloids is essential because their properties allow them to be separated from other types of mixtures, specifically colloids, through various processes.

Colloids

Unlike crystalloids, colloids consist of larger particles that do not dissolve completely. This particle size difference plays a crucial role in separation techniques such as dialysis. Due to their relatively larger particle size, colloids are unable to pass through semi-permeable membranes, which is key in processes that aim to keep them separate from crystalloids.

Colloids can be seen in everyday materials such as:

• Milk, where liquid fat particles are dispersed in water.
• Paint, where solid particles spread evenly in a liquid medium.
• Fog, where tiny droplets of water are suspended in air.

Understanding colloids helps in explaining why certain separation methods, like filtration, are effective in processing and purifying mixtures.

Filtration

Filtration is a separation technique used to divide components based on their particle size. In the context of dialysis, filtration allows the passage of small crystalloid particles through a semi-permeable membrane, while larger colloidal particles are retained.

The process involves:

• A semi-permeable membrane that allows only particles of a certain size to pass through.
• The application of pressure or force to push the smaller particles through, leaving larger ones behind.
• Commonly used not only in dialysis but also in water purification and in laboratories for separating components of liquid mixtures.

This method is essential for understanding how dialysis works, as it relies on the principles of filtration to achieve the separation of molecules based on size.

Semi-permeable membrane

A semi-permeable membrane is crucial for processes such as dialysis because it allows selective permeability. This means only certain substances, typically smaller particles like those in crystalloids, can pass through, while larger ones such as colloid particles are stopped.

The properties of a semi-permeable membrane include:

• Selective passage of specific molecules based on size and sometimes charge.
• Essentially acts as a filter enabling purification and separation of components in mixtures.
• Widely used in various applications, from dialysis machines in medical settings to food technology, such as in the preservation of products.

Understanding how a semi-permeable membrane functions is vital in comprehending processes that require separation of substances, particularly in the medical field with dialysis procedures.