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

The correct set of raw materials is \(\mathrm{NaCl}, \mathrm{NH}_{3}, \mathrm{CO}_{2}\) (option c).

Step-by-step solution

Identify the process

The Solvay process is an industrial method for producing sodium carbonate (\(\mathrm{Na}_2\mathrm{CO}_3\)). It primarily involves the reaction of sodium chloride (\(\mathrm{NaCl}\)), ammonia (\(\mathrm{NH}_3\)), and carbon dioxide (\(\mathrm{CO}_2\)).

Analyze raw material options

Given the options, we need the raw materials that match the starting substances of the Solvay process. The essential raw materials for the process are: \(\mathrm{NaCl}\), \(\mathrm{NH}_{3}\), and \(\mathrm{CO}_{2}\).

Match with provided options

Option (c) provides the correct set of materials: \(\mathrm{NaCl}\), \(\mathrm{NH}_{3}\), and \(\mathrm{CO}_{2}\). The other options include incorrect substances such as \(\mathrm{CaCl}_2\), \(\mathrm{NaOH}\), or \(\mathrm{Ca(OH)}_2\) which are not used in the initial steps of the Solvay process.

Key concepts

Sodium Carbonate Production

Sodium carbonate, commonly known as soda ash or washing soda, is primarily produced by the Solvay process. This method revolutionized industrial chemistry because it allowed for a more economical production of sodium carbonate compared to earlier methods. Soda ash is a significant chemical, used in everything from glass manufacturing to household cleaning products.

During the Solvay process, sodium chloride ( NaCl ), also known as common salt, reacts with ammonia ( NH_3 ) and carbon dioxide ( CO_2 ) to produce sodium carbonate ( Na_2CO_3 ). A key feature of this process is its cycle of reactions where by-products are continually reused, enhancing efficiency and reducing waste. This cyclical nature of the Solvay process not only makes it economically viable but also environmentally friendly.

Industrial Chemistry Process

The Solvay process is notable as a classic example of an industrial chemistry process. It embodies principles of chemistry that are applied on a large scale to make chemical products that we use in our daily lives. This process operates through interconnected steps, each designed to maximize yield and efficiency.

Initially, the brine solution ( NaCl ) is saturated with ammonia, and then carbon dioxide is bubbled through this mixture. The resulting reaction forms ammonium bicarbonate, which reacts with sodium chloride to form ammonium chloride and sodium bicarbonate. Upon heating, sodium bicarbonate decomposes to form sodium carbonate. Lastly, the ammonia is recovered for reuse, demonstrating the process's cyclical efficiency. This highlights how chemistry is scaled in industrial settings without compromising cost-effectiveness or sustainability.

Raw Materials in Chemistry

Raw materials are the building blocks of any chemical process. In the Solvay process, the primary raw materials are sodium chloride ( NaCl ), ammonia ( NH_3 ), and carbon dioxide ( CO_2 ). These compounds are crucial as they form the basis of the chemical reactions involved in producing sodium carbonate.

Understanding these raw materials' function is fundamental. Sodium chloride provides the sodium ions necessary for soda ash production. Ammonia acts as a catalyst and buffering agent, facilitating crucial reactions and is later recovered to minimize waste. Meanwhile, carbon dioxide is an essential reactant that helps precipitate sodium bicarbonate from the reaction mixture. Efficient management and use of these raw materials are pivotal in achieving the Solvay process's desired outcome.

Sodium Chloride as Reactant

Sodium chloride ( NaCl ) plays a pivotal role as a reactant in the Solvay process. Often dubbed as common salt, it is a readily available and inexpensive material, making it ideal for large-scale chemical production. In the context of the Solvay process, sodium chloride is primarily responsible for providing sodium ions which are essential for the creation of sodium carbonate.

During the process, NaCl is dissolved in water to form brine, which is then treated with ammonia and carbon dioxide to induce a series of reactions. Even though sodium chloride starts the cycle, it is not consumed entirely as the Solvay process includes mechanisms to recycle components wherever possible. This characterizes the ingenuity behind choosing NaCl as a reactant – it optimizes both resource usage and process efficiency, reflecting thoughtful industrial planning in chemical processes.