Problem 158 - A Complete Resource Book in Chemistry for JEE Main

Question

$$ \begin{aligned} &\text { Match the following }\\\ &\begin{array}{ll} \hline \text { Column-I} \text {Column-II } \\ \hline \begin{array}{ll} \text { (a) } \mathrm{Na}_{2} \mathrm{CO}_{3} & \text { (p) SO }_{2} \text { absorber } \\ \text { (b) } \mathrm{Na}_{2} \mathrm{SO}_{3} & \text { (q) Detergent } \\ \text { (c) } \mathrm{NaOH} & \text { (r) Glass } \\ \text { (d) } \mathrm{NaOCl} & \text { (s) Bleach } \\ \hline \end{array} \end{array} \end{aligned} $$

Step-by-Step Solution

Answer

(a) - (r), (b) - (p), (c) - (q), (d) - (s)

Step 1: Analyze Na2CO3

Examine the compound \(\text{Na}_{2}\text{CO}_{3}\), also known as washing soda. It is commonly used in the production of glass and in cleaning applications as a water-softening agent. Therefore, it matches with \(\text{r) Glass}\).

Step 2: Analyze Na2SO3

Consider the compound \(\text{Na}_{2}\text{SO}_{3}\), sodium sulfite. It is often used in the paper industry and in water treatment processes to remove oxygen and as a preservative. Notably, it is used to absorb sulfur dioxide, \(\text{SO}_{2}\), making it a match with \(\text{p) SO}_{2} \text{ absorber}\).

Step 3: Analyze NaOH

Review the compound \(\text{NaOH}\), also known as sodium hydroxide or caustic soda. Sodium hydroxide is frequently used to manufacture soaps and detergents due to its strong alkaline properties, matching it with \(\text{q) Detergent}\).

Step 4: Analyze NaOCl

Look at the compound \(\text{NaOCl}\), which is sodium hypochlorite. It is the main component in laundry bleach and is used for bleaching and disinfection, which aligns it with \(\text{s) Bleach}\).

Key Concepts

Na2CO3 (sodium carbonate)

Sodium carbonate, known as Na\(_2\)CO\(_3\), is a very versatile chemical compound. Often referred to as "washing soda," it is widely used in many household and industrial applications. One of its primary uses is in the manufacturing of glass. When making glass, sodium carbonate acts as a flux to lower the melting temperature of silica, making the process more efficient. This ability to lower melting points makes Na\(_2\)CO\(_3\) an essential additive.

Aside from glass production, sodium carbonate is equally important in household cleaning. It functions as a water softener. By reacting with calcium ions in water, Na\(_2\)CO\(_3\) prevents the buildup of limescale and improves the effectiveness of detergents.

• Primary Use: Glass manufacture
• Common Name: Washing soda
• Additional Uses: Water softening, cleaning agent

Na2SO3 (sodium sulfite)

Sodium sulfite, symbolized by Na\(_2\)SO\(_3\), plays a vital role in various industries, particularly in the paper production industry. It is primarily used to remove excess oxygen from the paper, improving the quality of the paper.

Another significant function of sodium sulfite is its role as a sulfur dioxide (SO\(_2\)) absorber. In industrial processes, Na\(_2\)SO\(_3\) helps in scrubbing sulfur dioxide from emissions, playing a part in pollution control. This makes it crucial in efforts to reduce sulfur emissions in the atmosphere.

Sodium sulfite is also utilized in water treatment to dechlorinate and purify water, showcasing its versatility.

• Industry Use: Paper production
• Environmental Role: SO\(_2\) absorption
• Water Treatment: Dechlorination

NaOH (sodium hydroxide)

Sodium hydroxide, bearing the chemical formula NaOH, is one of the strongest alkaline substances available. It is also known as caustic soda. Due to its strong alkaline nature, it’s extensively used in the production of soaps and detergents. The compound works by saponification, a process that transforms fats into soap and glycerol.

Apart from its primary use in cleaning agents, sodium hydroxide serves various roles in the chemical industry. This includes the manufacturing of paper, alumina, and textiles. It’s also commonly used in the process of refining petroleum products.

• Main Application: Detergent production
• Other Uses: Soap making, paper manufacturing, alumina production
• Alternate Name: Caustic soda

NaOCl (sodium hypochlorite)

Sodium hypochlorite, known by the formula NaOCl, is most commonly recognized as the active ingredient in bleach. This compound has potent disinfectant and bleaching properties, making it invaluable in household cleaning and sanitation.

In households, sodium hypochlorite is used to remove stains and disinfect various surfaces, ensuring hygienic conditions. Additionally, it is vital in water purification processes, where it is used for disinfecting and controlling odors.

• Most Common Use: Bleach
• Household Role: Disinfectant and stain removal
• Water Treatment: Purification and odor control