Question

\(\mathrm{N}_{2}(\mathrm{~g})+3 \mathrm{H}_{2}(\mathrm{~g}) \rightleftharpoons 2 \mathrm{NH}_{3}+22.4 \mathrm{kcal}\) formation of \(\mathrm{NH}_{3}\) by above reaction shows: (a) Cyanamide process (b) Serpeck's process (c) Haber process (d) None of these

Short answer

The formation of NH₃ in this reaction is the Haber process (c).

Step-by-step solution

Identify the Reaction Type

The reaction presented is the formation of ammonia (NH₃) from nitrogen (N₂) and hydrogen (H₂). This process includes ammonia as a product.

Analyze the Reaction Condition

The equation shows the synthesis of ammonia that also releases heat (22.4 kcal), indicating that this is an exothermic process. This is a typical characteristic of the Haber process.

Determine the Process

The Haber process is specifically known for synthesizing ammonia from nitrogen and hydrogen gases under high pressure and temperature, making it an exothermic process.

Key concepts

Ammonia Synthesis

Ammonia synthesis is the chemical process of creating ammonia, which has the chemical formula \(\mathrm{NH}_{3}\). This process involves combining nitrogen gas \(\mathrm{N}_{2}\) from the air with hydrogen gas \(\mathrm{H}_{2}\) mainly obtained from natural gas. Ammonia is a crucial component in fertilizers, and its production is vital to agricultural industries worldwide. The most well-known method of synthesizing ammonia is the Haber Process.

• In the Haber Process, nitrogen and hydrogen gases are introduced into the reaction chamber.
• The reaction occurs at high pressures, typically around 200 atmospheres, to encourage the gases to combine.
• High temperatures, about 450°C, are also maintained along with an iron catalyst to speed up the reaction.

These conditions help overcome the natural stability of nitrogen due to its triple bond, which is challenging to break under normal conditions. The synthesis process is vital as it impacts global food supplies by enabling mass production of fertilizers.

Exothermic Reaction

An exothermic reaction is one that releases energy in the form of heat. During these reactions, the energy necessary to break the bonds in reactants is less than the energy released when new bonds form in products. This indicates a release of energy, typically making the surroundings warmer.
In the case of the Haber Process for ammonia synthesis, the reaction:\[ \mathrm{N}_{2}(\mathrm{g}) + 3\mathrm{H}_{2}(\mathrm{g}) \rightleftharpoons 2\mathrm{NH}_{3} + 22.4 \mathrm{kcal} \]illustrates an exothermic process.

• The transition from nitrogen and hydrogen to ammonia is accompanied by a release of 22.4 kcal of heat per mole of reaction.
• Exothermic reactions often favor conditions such as lower temperatures to maximize product formation.

However, for industrial purposes, the ammonia synthesis reaction is conducted under higher temperatures to ensure a sufficiently fast reaction rate, even if it slightly shifts the equilibrium towards the reactants.

Chemical Equilibrium

Chemical equilibrium in a chemical reaction is achieved when the rate of the forward reaction equals the rate of the reverse reaction. This state indicates that the concentrations of reactants and products remain constant over time, though they are not necessarily equal.
For ammonia synthesis in the Haber Process, equilibrium plays a critical role.

• The reaction can be represented by the double arrow \(\rightleftharpoons\), indicating that ammonia can decompose back into nitrogen and hydrogen under certain conditions.
• Catalysts, such as iron in the Haber Process, do not shift the position of the equilibrium but rather help the system reach equilibrium more quickly.
• Optimizing the pressure and temperature helps in favoring the formation of ammonia by shifting the equilibrium to the product side.

Understanding equilibrium is vital for the efficient production of ammonia, ensuring that production rates meet industrial demands while conserving energy and resources.