Problem 30 - 43 Years JEE ADVANCED (1978-2020) + JEE MAIN Chapterwise & Topicwise Solved Papers Chemistry

Question

Match the following compounds (Column-I) with their uses (Column-II): Column-I Column-II (I) \(\mathrm{Ca}(\mathrm{OH})_{2}\) (A) casts of statutes (II) \(\mathrm{NaCl}\) (B) white wash (III) \(\mathrm{CaSO}_{4} \cdot \frac{1}{2} \mathrm{H}_{2} \mathrm{O}\) (C) antacid \(\begin{array}{lll}\text { (IV) } & \mathrm{CaCO}_{3} & \text { (D) washing soda }\end{array}\) preparation (a) (I)- \((\mathrm{D}),(\mathrm{II})-(\mathrm{A}),(\mathrm{III})-(\mathrm{C}),(\mathrm{IV})-(\mathrm{B})\) (b) \((\mathrm{I})-(\mathrm{B}),(\mathrm{II})-(\mathrm{D}),(\mathrm{III})-(\mathrm{A}),(\mathrm{IV})-(\mathrm{C})\) (c) \((\mathrm{I})-(\mathrm{B}),(\mathrm{II})-(\mathrm{C}),(\mathrm{III})-(\mathrm{D}),(\mathrm{IV})-(\mathrm{A})\) (d) \((\mathrm{I})-(\mathrm{C}),(\mathrm{II})-(\mathrm{D}),(\mathrm{IIl})-(\mathrm{B}),(\mathrm{IV})-(\mathrm{A})\)

Step-by-Step Solution

Answer

The correct matches are option (b).

Step 1: Identify the Use of Calcium Hydroxide

Calcium hydroxide, \(\mathrm{Ca(OH)}_{2}\), is commonly used in whitewashing. This is a traditional use due to its ability to form a soft, adhesive layer when applied to walls.

Step 2: Identify the Use of Sodium Chloride

Sodium chloride, \(\mathrm{NaCl}\), is common table salt but also used in the preparation of washing soda by reacting with other chemicals like ammonia and carbon dioxide.

Step 3: Identify the Use of Plaster of Paris

Calcium sulfate hemihydrate, \(\mathrm{CaSO}_{4} \cdot \frac{1}{2} \mathrm{H}_{2}\mathrm{O}\), is better known as plaster of Paris. It is used to make casts and statues due to its ability to harden when mixed with water.

Step 4: Identify the Use of Calcium Carbonate

Calcium carbonate, \(\mathrm{CaCO}_{3}\), is often used as an antacid because it neutralizes stomach acid.

Step 5: Match the Compounds with Their Uses

Using the identified uses, the correct matches are: \((\mathrm{I})-(\mathrm{B})\), \((\mathrm{II})-(\mathrm{D})\), \((\mathrm{III})-(\mathrm{A})\), \((\mathrm{IV})-(\mathrm{C})\). This corresponds to option (b).

Key Concepts

Calcium Hydroxide Uses

Calcium hydroxide, also known as slaked lime, is a compound commonly leveraged in various industrial and domestic applications. One of its most recognizable uses is in whitewashing, a technique frequently employed for brightening the exteriors of houses, fences, and other structures. This compound's ability to form a smooth, adhesive film makes it ideal for this purpose, providing aesthetic and protective qualities.
Moreover, calcium hydroxide serves in the construction industry by improving the quality of cement. It acts as a crucial component that helps in stabilizing soil and modifying its properties for better durability and workability.
Another utility in agriculture is for soil stabilization and pH adjustment, enhancing the quality of acidic soil for better crop yield. This versatility makes calcium hydroxide an indispensable material in many sectors.

Sodium Chloride Applications

Sodium chloride, most commonly known as table salt, extends its applications far beyond the dining table. Beyond its role in food seasoning and preservation, it is pivotal in several industrial processes.

• In chemical manufacturing, sodium chloride is a primary source for the chlor-alkali industry, leading to the production of key chemicals like chlorine, sodium carbonate, and sodium hydroxide.
• It plays a role in de-icing roads in winter, helping to keep surfaces safe by lowering the freezing point of water.
• Additionally, sodium chloride is used in the preparation of washing soda, or sodium carbonate, which is essential for laundry detergents and other cleaning agents.

Its versatility in industrial and everyday applications highlights sodium chloride’s importance beyond just food flavoring.

Plaster of Paris

Plaster of Paris is the common name for calcium sulfate hemihydrate, (\( \mathrm{CaSO}_{4} \, \cdot \, \frac{1}{2} \mathrm{H}_{2} \mathrm{O} \)). This compound is renowned for its ability to form a sturdy and smooth surface upon hardening.
One fascinating property of plaster of Paris is its rapid setting time. When mixed with water, it re-forms into a gypsum paste, which quickly hardens, making it ideal for medical use in cast applications to immobilize broken bones.
Artists and builders appreciate it for creating ornate columns, statues, and sculptures. Its ease of use and quick drying time offer a preferred medium for artistic and architectural projects. As such, plaster of Paris continues to be a vital material across different creative and functional domains.

Calcium Carbonate Functions

Calcium carbonate is an abundant mineral found naturally in rocks such as limestone, marble, and chalk. It serves a multitude of functions in various industries due to its chemical and physical properties.
In healthcare, it is a potent antacid used to neutralize stomach acids, providing relief from conditions like heartburn and acid indigestion. This protective buffering ability underscores its significance in medicinal applications.

• In construction, calcium carbonate acts as a building material in its primary forms, like limestone and marble, integral for creating durable structures.
• Additionally, it is used as a whitening agent in the paper industry, improving the brightness and sheen of paper products.
• It also finds its role as a dietary calcium supplement to support bone health.

Thus, calcium carbonate's diverse functionalities make it indispensable in both commercial and health-related fields.