Problem 33 - A Complete Resource Book in Chemistry for JEE Main

Question

\(\mathrm{N}_{2}(\mathrm{~g})+3 \mathrm{H}_{2}(\mathrm{~g})=\frac{\mathrm{Fe} / \mathrm{Mo}, 500^{\circ} \mathrm{C}}{=\mathrm{V} 200-900 \mathrm{~atm}} 2 \mathrm{NH}_{3}+22.4\) kcal formation of \(\mathrm{NH}_{3}\) by above reaction shows (a) Cyanamide process (b) Serpeck's process (c) Haber process (d) None of these

Step-by-Step Solution

Answer

(c) Haber process

Step 1: Understanding the Reaction Setup

The chemical equation provided represents a reaction where nitrogen gas (\(\text{N}_2(g)\)) and hydrogen gas (\(\text{H}_2(g)\)) react to form ammonia (\(\text{NH}_3\)). This reaction is catalyzed by iron-molybdenum (\(\text{Fe/Mo}\)) at high temperatures around 500°C and under high pressures from 200 to 900 atm.

Step 2: Identifying the Process

The description of high temperature and pressure conditions, along with the use of a catalyst, are key features of a specific industrial process for producing ammonia. This specific approach is known for the synthesis of ammonia large-scale production.

Step 3: Connecting Process to Options

The options given are different industrial processes related to ammonia and its precursors. The Haber process is specifically designed for the synthesis of ammonia under the conditions mentioned. The other processes listed do not directly correlate to ammonia synthesis as described.

Key Concepts

Ammonia Synthesis

Ammonia synthesis is a critical chemical reaction used to produce ammonia, a vital compound in the industry. The reaction involves nitrogen gas (\(\text{N}_2\)) and hydrogen gas (\(\text{H}_2\)) combining under specific conditions to form ammonia (\(\text{NH}_3\)). This synthesis is essential because ammonia serves as a precursor for fertilizers, and thus, is a key player in agriculture. The simplest form of the chemical equation representing this reaction is:\[ \text{N}_2(g) + 3\text{H}_2(g) \rightarrow 2\text{NH}_3(g) \]This reaction is exothermic, meaning it releases heat, and requires a catalyst to proceed efficiently due to the naturally high energy barrier. By utilizing catalysts and manipulating temperature and pressure, industrial processes optimize this reaction to meet the vast demand for ammonia worldwide.

Industrial Chemistry

In the realm of industrial chemistry, the production of ammonia is a cornerstone. Industrial chemistry focuses on transforming raw materials into valuable products through chemical processes. One of the most iconic processes in this field is the Haber process, developed to synthesize ammonia on an industrial scale. This process showcases industrial chemistry's ability to overcome natural limitations, like the inaccessibility of nitrogen gas due to its strong triple bond. By operating at high temperatures (around 500°C) and pressures (200-900 atm), and using iron-based catalysts, this process efficiently produces ammonia, demonstrating the triumph of industrial chemistry over challenging chemical scenarios. Critical use cases include:

• Fertilizer production, supporting global food supply.
• Manufacture of explosives and other chemicals.

Overall, industrial chemistry turns scientific principles into practical, economic solutions that fuel global industries.

Catalysis

Catalysis is a crucial phenomenon that enhances the rate of chemical reactions without being consumed in the process. In ammonia synthesis, catalysis is essential for practical and economic production. The Haber process relies on iron-based catalysts (often enhanced with molybdenum) to aid the conversion of nitrogen and hydrogen into ammonia. Using a catalyst in this context allows:

• Reduction in activation energy, speeding the reaction.
• Increased yields of ammonia at feasible environmental conditions.
• Industry-scale sustainability by minimizing energy consumption.

Catalysts are carefully chosen to ensure they are effective under the process conditions and can withstand the rigors of industrial operations, making them indispensable in processes like ammonia synthesis.

Chemical Engineering

Chemical engineering plays a pivotal role in designing and optimizing processes like the Haber process for ammonia production. This engineering branch applies principles of physics, chemistry, and mathematics to develop efficient processes for manufacturing chemical products. Chemical engineers working on ammonia synthesis focus on:

• Optimizing reactor designs to enhance conversion rates.
• Managing heat and mass transfer to maintain process efficiency.
• Minimizing costs associated with energy consumption and raw materials.

They are critical in scaling laboratory reactions into industrial operations that can safely and economically meet global demands. Thus, chemical engineers transform theoretical chemistry concepts into tangible industrial processes, ensuring the sustainable production of vital chemicals like ammonia.