Problem 53 - A Complete Resource Book in Chemistry for JEE Main

Question

Plaster of paris is used (a) in dentistry and surgery (b) as a plaster for walls (c) as a drying agent (d) in metallurgical process

Step-by-Step Solution

Answer

The correct answers are (a) in dentistry and surgery and (b) as a plaster for walls.

Step 1: Understand the Question

We need to determine the primary or most common uses of plaster of Paris by identifying which of the given options it is typically employed in.

Step 2: Evaluate Option (a)

Plaster of Paris is commonly used in dentistry for making dental molds and in surgery to create casts for broken bones. This suggests option (a) could be correct.

Step 3: Evaluate Option (b)

Plaster of Paris is applied as a plaster for walls or ceilings in the construction industry. This indicates option (b) could also be a correct choice.

Step 4: Evaluate Option (c)

Plaster of Paris is not typically used as a drying agent. This means option (c) is likely incorrect.

Step 5: Evaluate Option (d)

Plaster of Paris is not commonly used in metallurgical processes, so option (d) is unlikely to be correct.

Step 6: Determine Correct Answers

Since both options (a) and (b) describe common uses of plaster of Paris, these are the correct answers to the question.

Key Concepts

uses in dentistry

Plaster of Paris plays a crucial role in the field of dentistry, thanks to its ability to easily mold and take precise shapes. This property makes it an indispensable material for creating dental molds. These molds are used by dentists to make impressions of a patient's teeth and gums. Such impressions are essential when designing dentures or dental prosthetics that fit perfectly. This ensures that any artificial dental pieces created are comfortable and functional for the patient.
Plaster of Paris is preferred in this field due to its:

• Easy workability
• Ability to capture fine details
• Quick setting time
• Low cost

The material’s adaptability means it can be quickly manipulated into different shapes before it hardens, allowing for precise replicas of dental structures. The reliability and convenience of plaster of Paris in dental healthcare make it a standard choice.

uses in surgery

In surgical settings, plaster of Paris is instrumental in the treatment of broken bones. Surgeons utilize it to create casts that stabilize fractures during the healing process. The cast encases the injured limb, providing a firm support structure that keeps bones aligned and immobile. This immobility is key to proper bone healing as it allows the body's natural repair processes to occur without disruption.
Key benefits of using plaster of Paris in surgery include:

• Strength and durability once set
• Ability to contour to the body
• Light weight compared to metal alternatives
• Non-toxic and safe for skin contact

While modern medicine has introduced synthetic casting materials, plaster of Paris remains exceptionally useful, especially for short-term applications and in situations where cost-effectiveness is a concern.

construction applications

In the construction industry, plaster of Paris is extensively used for coating walls and ceilings. The smooth finish it provides is aesthetically pleasing and highly effective in creating a flat base for painting or wallpapering. Plaster of Paris can fill in small cracks and imperfections, enhancing the structural integrity and look of the surfaces it covers.
Some advantages of using plaster of Paris in construction include:

• Ease of application
• Ability to dry quickly
• Malleability before setting, allowing for decorative moldings
• Cost-efficiency

Its versatility means that plaster of Paris is not only used for plain wall applications but also for artistic design purposes such as creating detailed cornices and moldings. Overall, its role in construction aids in both the foundational and decorative aspects of building work.