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

The product is (a) \(\mathrm{CaC}_2\), calcium carbide.

Step 1: Understanding the Question

The question asks what the product is when quick lime (which is calcium oxide, \(\mathrm{CaO}\)) is heated with coke in an electric furnace. We need to identify the chemical reaction and its product.

Step 2: Recall Reactants

Quick lime is \(\mathrm{CaO}\) and coke is primarily carbon (\(\mathrm{C}\)). When these are reacting together, we must determine the likely chemical reaction and products formed.

Step 3: Write the Chemical Reaction

The reaction of quick lime with coke generally produces calcium carbide \((\mathrm{CaC}_2)\). The chemical equation is: \[ \mathrm{CaO} + 3\mathrm{C} \rightarrow \mathrm{CaC}_2 + \mathrm{CO} \]

Step 4: Identify the Product

From the equation, the main product of the reaction is \(\mathrm{CaC}_2\) which is known as calcium carbide.

Step 5: Match the Reaction Product with Given Options

Compare the products from the chemical equation to the options given:- (a) \(\mathrm{CaC}_2\)- (b) \(\mathrm{CaCO}_3\)- (c) \(\mathrm{CaO}\)- (d) \(\mathrm{Ca}\) and \(\mathrm{CO}_2\)The correct match is option (a) \(\mathrm{CaC}_2\), which is calcium carbide.

Key Concepts

Chemical Reactions

Chemical reactions are processes where reactants are transformed into products through breaking and forming of chemical bonds. These transformations can involve solids, liquids, gases, or even combinations of these states. Consider the reaction of quick lime (calcium oxide) with coke as an example.
Here, the reactants are quick lime, \( \text{CaO} \), and coke, primarily made of carbon, \( \text{C} \). These two substances react in an electric furnace which provides the necessary heat to initiate the transformation. The reaction leads to the formation of calcium carbide, \( \text{CaC}_2 \), and carbon monoxide, \( \text{CO} \).
Understanding the type of substances involved and the conditions (like temperature and pressure) is crucial in predicting the products of such reactions. In this case, the involvement of intense heat from an electric furnace is essential for the reaction to proceed.

Quick Lime

Quick lime, also known as calcium oxide, is a widely used chemical compound. It is a white, caustic, alkaline substance produced by strongly heating calcium carbonate (limestone). This heating process is called calcination and the chemical reaction can be represented as:\[ \text{CaCO}_3 \rightarrow \text{CaO} + \text{CO}_2 \]
Calcium oxide is a versatile material with applications ranging from construction to specialty ceramics. It's used in the making of cement, and also plays a role in the production of steel. In the case of the chemical reaction with coke, quick lime provides the necessary calcium component to form calcium carbide.
Always handle quick lime with care, as it reacts exothermically with water, potentially causing burns.

Calcium Oxide

Calcium oxide, often called quick lime, is a significant mineral in various chemical processes. Its reactivity makes it a crucial reactant in certain high-temperature chemical reactions, like producing calcium carbide.
In the reaction with coke, calcium oxide acts as a base that reacts with the carbon to form calcium carbide (\( \text{CaC}_2 \)). Beyond this specific reaction, calcium oxide is useful for neutralizing acids and removing impurities in metallurgical processes. It is important in the glass industry, used in making lime glass through the \( \text{CaO} \) component.
When interacting with carbon, as in this case, \( \text{CaO} \) forms part of a unique reaction pathway that highlights its versatility as a chemical reactant.

Coke

Coke is a form of carbon used in various chemical reactions, especially those requiring high temperatures. It is generated by destructive distillation of coal, resulting in a porous, dense product rich in carbon.
Coke serves as both a fuel and a reducing agent in metallurgical processes like iron production and in this specific reaction involving calcium oxide. Here, coke reacts with \( \text{CaO} \) under high heat to produce calcium carbide (\( \text{CaC}_2 \)) and carbon monoxide (\( \text{CO} \)). This reaction highlights coke's importance in creating industrially valuable compounds through its interaction with elements such as calcium.
The ability of coke to withstand high temperatures while providing necessary carbon makes it an indispensable material in chemical industries, reflecting its critical role in the production of materials like calcium carbide.