Problem 73 - A Complete Resource Book in Chemistry for JEE Main

Question

Ammonia reacts with sodium hypochlorite to give (a) \(\mathrm{N}_{2} \mathrm{O}\) (b) \(\mathrm{N}_{2}\) (c) \(\mathrm{NH}_{2} \mathrm{OH}\) (d) \(\mathrm{H}_{2} \mathrm{~N} \cdot \mathrm{NH}_{2}\)

Step-by-Step Solution

Answer

The product is nitrogen gas (N₂).

Step 1: Identify Reactants and Products

The reaction involves ammonia, which is NH₃, reacting with sodium hypochlorite, which is NaOCl. We need to deduce the correct product from the given options: (a) N₂O, (b) N₂, (c) NH₂OH, and (d) H₂N·NH₂.

Step 2: Consider Chemical Possibilities

In chemical reactions, especially involving ammonia and sodium hypochlorite, common products include nitrogen gas (N₂), hydrazine (N₂H₄), and other nitrogen-containing compounds. Recall basic reaction theories and previous knowledge.

Step 3: Eliminate Incorrect Options

N₂O is dinitrogen monoxide (laughing gas), but this is not a common product when ammonia reacts with sodium hypochlorite. Similarly, NH₂OH (hydroxylamine) is also unlikely to form in such basic oxidative reactions.

Step 4: Determine Likely Product

In reactions involving NH₃ and NaOCl, one common combination forms nitrogen gas (N₂) and water due to complete oxidation of ammonia. Alternatively, more complex reactions can yield H₂N·NH₂ (hydrazine).

Step 5: Final Decision

The most likely product from the multiple-choice options, given the reactants, is nitrogen gas (N₂). In many lessons and examples, ammonia oxidation by a hypochlorite results in nitrogen gas formation.

Key Concepts

Chemical Reaction Products

In any chemical reaction, recognizing the resulting products is crucial. A chemical reaction involves reactants undergoing transformation to form new substances. The products of a reaction are determined by the nature of the reactants and their interaction during the reaction.
For the reaction between ammonia (NH₃) and sodium hypochlorite (NaOCl), identifying the possible products relies on understanding the chemical properties of the reactants. Common knowledge teaches us that when these two substances react, the primary products are nitrogen-containing compounds.

• Often, nitrogen gas (_2) is formed from the complete oxidation of ammonia.
• Depending on conditions, you might also get hydrazine (H88).

Understanding which products are likely requires us to consider the specific circumstances of the reaction, such as concentration and temperature. In the given exercise, nitrogen gas (N₂) was identified as the most probable product.

Oxidation of Ammonia

Oxidation reactions involve the transfer of electrons, traditionally seen as a substance losing electrons. When ammonia undergoes oxidation, it gains oxygen or loses hydrogen, often resulting in nitrogen molecule formations.
Ammonia starts out as NH₃, a rather basic and common nitrogen compound used often in household cleaning products. As an oxidation process occurs—especially in the presence of a strong oxidizing agent like sodium hypochlorite—the N−H bonds in ammonia break down.
The oxidation results often outline:

• The transformation of NH₃ into nitrogen gas (N₂) when it loses complete hydrogen and gains oxygen.
• Possibility of creating other nitrogen-based substances, under less common conditions.

This knowledge underscores the primary role of ammonia in many industrial and laboratory settings, showcasing its versatility in producing various nitrogen compounds.

Nitrogen Compounds

Nitrogen compounds are an extensive family within chemistry, characterized by nitrogen atoms bonded with various other elements. These compounds range from simple diatomic nitrogen (N₂) to more complex structures like hydrazine (N₂H₄).
In reactions like the one between ammonia and sodium hypochlorite, it’s important to recognize:

• Nitrogen gas (N₂) is the most stable and abundant form found naturally.
• Hydrazine (N₂H₄) emerges as a derivative involving ammonia under specific conditions.

These compounds have a wide range of applications. For example, N₂ is used in inert atmospheres for chemical manufacturing and as a preservative for perishable items. Meanwhile, N₂H₄ finds roles in fuel for rocket propellants due to its reactive nature. Understanding these compounds helps predict the behavior and products of chemical reactions, especially in industrial applications.

Sodium Hypochlorite Chemistry

Sodium hypochlorite (NaOCl) is a versatile chemical often used as a bleaching agent or disinfectant. It is a powerful oxidizing agent, meaning it can accept electrons from another substance, facilitating chemical reactions.
In the context of reacting with ammonia, sodium hypochlorite's chemistry is essential to examine because:

• Its role as an oxidizing agent allows it to transform ammonia into nitrogen-containing products.
• It can drive the complete oxidation to yield the more stable nitrogen gas (N₂) under proper conditions.

Generally, sodium hypochlorite’s efficacy makes it a staple in various cleaning formulations and chemical syntheses. Understanding its chemical characteristics and behavior in reactions aids in predicting and utilizing its potential to produce desired chemical compounds efficiently.