Problem 57 - A Complete Resource Book in Chemistry for JEE Main

Question

On heating quick lime with coke in an electric furnace, we get (a) \(\mathrm{CaC}_{2}\) (b) \(\mathrm{CaCO}_{3}\) (c) \(\mathrm{CaO}\) (d) \(\mathrm{Ca}\) and \(\mathrm{CO}_{2}\)

Step-by-Step Solution

Answer

(a) \(\mathrm{CaC}_{2}\) is formed.

Step 1: Understanding the Reaction

The given problem involves the reaction of quick lime (\(\mathrm{CaO}\)) with coke (carbon, \(\mathrm{C}\)) in an electric furnace. This is a known process used in industry.

Step 2: Write the Chemical Equation

The chemical reaction can be represented as \[\mathrm{CaO} + 3 \mathrm{C} \rightarrow \mathrm{CaC}_{2} + \mathrm{CO}.\] This reaction takes place when quick lime is heated with coke.

Step 3: Determine the Product

The product of this reaction is calcium carbide (\(\mathrm{CaC}_{2}\)) along with carbon monoxide (\(\mathrm{CO}\)). Therefore, the correct answer is the compound formed, \(\mathrm{CaC}_{2}\).

Key Concepts

The Role of Quick Lime

Quick lime, also known as calcium oxide (\(\mathrm{CaO}\)), plays a pivotal role in various industrial chemical processes. It is commonly produced by heating limestone (calcium carbonate, \(\mathrm{CaCO}_{3}\)) in a process known as calcination, where it decomposes to form quick lime and carbon dioxide.

Quick lime is highly reactive and serves as a crucial reactant in the production of calcium carbide.

• It acts as a source of calcium in the reaction.
• It readily combines with the carbon present in coke to form the desired product.

Understanding calcium oxide’s properties and reactivity is essential in predicting the outcomes of the processes it is involved in.

Understanding Coke in Chemical Processes

Coke is a type of carbon material derived from coal, used extensively in chemical processes such as the production of calcium carbide.

When processing coke, its carbon content is critical since it engages in the chemical reaction with quick lime inside the electric furnace.

• Coke’s primary role is to provide the necessary carbon atoms for the reaction.
• By reacting with \(\mathrm{CaO}\), it helps in forming the calcium carbide and carbon monoxide.

Coke’s composition and efficiency can significantly influence the overall process, making its selection an essential step in industrial chemical applications.

Key Chemical Reactions in Calcium Carbide Production

Chemical reactions are the backbone of calcium carbide production.

The specific reaction we focus on here involves the interaction between quick lime and coke:\[\mathrm{CaO} + 3 \mathrm{C} \rightarrow \mathrm{CaC}_{2} + \mathrm{CO}.\]
This reaction is exothermic, meaning it releases heat as the reactants convert into products.

• The products of this reaction are calcium carbide (\(\mathrm{CaC}_{2}\)), widely used in various industries, and carbon monoxide (\(\mathrm{CO}\)), a gas that needs careful management due to its toxicity.
• The precise stoichiometry of the reaction plays a critical role in ensuring efficient production without excess waste.

Grasping these core principles helps in understanding not just the specific process, but also broader chemical reaction dynamics.

The Function of the Electric Furnace

In the production of calcium carbide, the electric furnace is indispensable. Its main function is to provide the necessary environment for the chemical reaction between quick lime and coke.

• The electric furnace reaches very high temperatures, ensuring the reactants are sufficiently heated for the reaction to occur.
• Given the endothermic nature of the reaction set up, a consistent and high level of heat is crucial.

These furnaces are specially designed to handle the intense heat and reactive environment, thereby safely containing the reaction products and maintaining process efficiency. Mastering the operation and maintenance of electric furnaces can lead to better productivity and safety in chemical manufacturing.