Question

Which of the following set of raw materials are used in the manufacture of \(\mathrm{Na}_{2} \mathrm{CO}_{3}\) by Solvay process? (a) \(\mathrm{CaCl}_{2}, \mathrm{NH}_{3}, \mathrm{CO}_{2}\) (b) \(\mathrm{NaOH}, \mathrm{NH}_{3}, \mathrm{CO}_{2}\) (c) \(\mathrm{NaCl}, \mathrm{NH}_{3}, \mathrm{CO}_{2}\) (d) \(\mathrm{Ca}(\mathrm{OH})_{2}, \mathrm{NH}_{3}, \mathrm{CO}_{2}\)

Short answer

Option (c) \(\mathrm{NaCl}, \mathrm{NH}_{3}, \mathrm{CO}_{2}\) is used in the Solvay process.

Step-by-step solution

Understand the Solvay Process

The Solvay process is an industrial method used to produce sodium carbonate (\(\mathrm{Na}_{2}\mathrm{CO}_{3}\)) from sodium chloride. It involves several chemical reactions, primarily using sodium chloride and ammonia as the raw materials.

Identify the Main Raw Materials for the Solvay Process

The main raw materials required for the Solvay process are sodium chloride (\(\mathrm{NaCl}\)), ammonia (\(\mathrm{NH}_{3}\)), carbon dioxide (\(\mathrm{CO}_{2}\)), and water. However, calcium carbonate is often used to generate carbon dioxide.

Evaluate Each Option

Now, let's evaluate each option to see which one includes sodium chloride, ammonia, and carbon dioxide.- (a) \(\mathrm{CaCl}_{2}, \mathrm{NH}_{3}, \mathrm{CO}_{2}\): This set doesn't include sodium chloride.- (b) \(\mathrm{NaOH}, \mathrm{NH}_{3}, \mathrm{CO}_{2}\): Sodium hydroxide is not used in the Solvay process.- (c) \(\mathrm{NaCl}, \mathrm{NH}_{3}, \mathrm{CO}_{2}\): This set includes all the main ingredients for the Solvay process.- (d) \(\mathrm{Ca(OH)}_{2}, \mathrm{NH}_{3}, \mathrm{CO}_{2}\): Calcium hydroxide is not a raw material for the Solvay process.

Key concepts

Sodium Chloride

Sodium chloride, commonly known as table salt, is a vital substance in both our daily life and industrial chemistry. Its chemical formula is \( \text{NaCl} \). It is a white crystalline solid that dissolves easily in water, creating a solution that is a good conductor of electricity. Sodium chloride is abundant on the earth's surface, primarily obtained from sea water or rock salt deposits.
In the Solvay process, sodium chloride is essential as the primary raw material for producing sodium carbonate. The Solvay process revolves around converting \( \text{NaCl} \) into \( \text{Na}_2\text{CO}_3 \), using a series of reactions that transform the mineral's chemical properties. Initially, sodium chloride is saturated with ammonia and carbon dioxide to produce ammonium chloride and sodium bicarbonate.
Understanding the role of \( \text{NaCl} \) helps in appreciating its contribution to industrial processes. While its most common use is in food preservation and seasoning, in industrial chemistry, it is a workhorse, particularly for sodium carbonate production.

Sodium Carbonate Production

Sodium carbonate, known as soda ash or washing soda, has the chemical formula \( \text{Na}_2\text{CO}_3 \). It is a white, soluble compound used extensively in manufacturing glass, detergents, and paper.
In the Solvay process, sodium carbonate is produced from sodium chloride, ammonia, and carbon dioxide. The reactions begin by mixing \( \text{NaCl} \) with \( \text{NH}_3 \) and \( \text{CO}_2 \) to form \( \text{NaHCO}_3 \) and \( \text{NH}_4\text{Cl} \).

• The sodium bicarbonate \( \text{NaHCO}_3 \) is then filtered out, leaving a solution of ammonium chloride.
• Afterwards, the sodium bicarbonate is heated, leading to decomposition into sodium carbonate, water, and carbon dioxide:

\[ 2 \text{NaHCO}_3 \rightarrow \text{Na}_2\text{CO}_3 + \text{CO}_2 + \text{H}_2\text{O} \]
This step regenerates carbon dioxide, which is recycled in the process. The Solvay process is an ingenious cycle that efficiently produces soda ash, minimizing waste and reusing materials whenever possible.

Industrial Chemistry

The field of industrial chemistry is about applying chemical and physical processes to transform raw materials into valuable everyday products. This branch of science underlies the functionality of industries, including plastics, pharmaceuticals, and, notably, chemical manufacturing.
The Solvay process is a classic example of an industrial chemistry method, showcasing how fundamental reactions can yield significant products like sodium carbonate. It highlights several key aspects of industrial chemistry:

• Efficiency: The process maximizes the use of resources, recycling ammonia and carbon dioxide.
• Scale: It enables mass production of important compounds, critical to a modern industrial economy.
• Safety and Environment: Innovations in industrial chemistry aim to reduce by-products and emissions.

Understanding how the Solvay process fits into industrial chemistry illustrates the discipline’s role in facilitating large-scale production while considering sustainability and economical resource use.
The blending of chemistry with industrial practices allows for continuous innovation and improvement in processes like the Solvay, adapting to new challenges and demands.