Problem 6 - A Complete Resource Book in Chemistry for JEE Main

Question

When sodium bicarbonate is heated, the product obtained is (a) \(\mathrm{Na}\) (b) \(\mathrm{NaCO}_{3}\) (c) \(\mathrm{NaHCO}_{3}\) (d) \(\mathrm{Na}_{2} \mathrm{CO}_{3}\)

Step-by-Step Solution

Answer

(d) {Na}_2 {CO}_3

Step 1: Understand the Chemical Reaction

When sodium bicarbonate ( ext{NaHCO}_{3} ) is heated, it decomposes. The chemical reaction is: 2 ext{NaHCO}_{3} ightarrow ext{Na}_{2} ext{CO}_{3} + ext{CO}_{2} + ext{H}_{2} ext{O} . From this reaction, we can see that sodium carbonate ( ext{Na}_{2} ext{CO}_{3}) is formed.

Step 2: Identify the Products

In the decomposition, the products formed are sodium carbonate ( ext{Na}_{2} ext{CO}_{3}), carbon dioxide ( ext{CO}_{2}), and water ( ext{H}_{2} ext{O}). Therefore, ext{Na}_{2} ext{CO}_{3} is the product we are interested in.

Step 3: Match the Product with the Options Provided

Among the given options: (a) ext{Na}, (b) ext{NaCO}_{3}, (c) ext{NaHCO}_{3}, and (d) ext{Na}_{2} ext{CO}_{3}, the correct product formed by the heating of sodium bicarbonate is ext{Na}_{2} ext{CO}_{3}.

Key Concepts

Chemical Reactions

In chemistry, reactions occur when substances interact with one another to create something new. For sodium bicarbonate - also known as baking soda - this means breaking down into different substances when heated.

• A chemical reaction involves breaking original bonds and creating new ones.
• In some reactions, energy is either absorbed or released, often in the form of heat.

A key part of understanding reactions is identifying the reactants and products. Here, the reactant is sodium bicarbonate (\(\mathrm{NaHCO}_{3}\)) and the products are sodium carbonate (\(\mathrm{Na}_{2} \mathrm{CO}_{3}\)), carbon dioxide (\(\mathrm{CO}_{2}\)), and water (\(\mathrm{H}_{2}\mathrm{O}\)).These transformations exemplify how matter undergoes changes through chemical reactions, often resulting in substances with completely different properties.

Thermal Decomposition

Thermal decomposition is a type of chemical reaction where a substance breaks down into simpler products when heat is applied.This process is crucial for understanding how certain compounds, like sodium bicarbonate, behave under heat.

• When heated, thermal energy overcomes the forces holding the molecules together, causing the bonds to break.
• This results in the formation of new substances that are more stable under the elevated temperature.

In the case of sodium bicarbonate, heating leads to its decomposition into sodium carbonate, carbon dioxide, and water. The balanced chemical equation is:\[2 \mathrm{NaHCO}_{3} \rightarrow \mathrm{Na}_{2}\mathrm{CO}_{3} + \mathrm{CO}_{2} + \mathrm{H}_{2}\mathrm{O}\]By decomposing (\( \mathrm{NaHCO}_{3} \)) through heat, we gain valuable products like \( \mathrm{Na}_{2}\mathrm{CO}_{3} \), a key compound with various applications.

Sodium Carbonate Formation

The formation of sodium carbonate from sodium bicarbonate is an interesting transformation in chemistry. This process is due to a breakdown known as thermal decomposition. The reaction results in the rearrangement of atoms to form entirely new compounds.

• Sodium carbonate (\(\mathrm{Na}_{2}\mathrm{CO}_{3}\)) is a primary product of this reaction and plays an important role in industrial applications.
• The release of carbon dioxide (\(\mathrm{CO}_{2}\)) and water (\(\mathrm{H}_{2}\mathrm{O}\)) also occurs during this transformation.

This simple thermal decomposition highlights how common materials can transform into valuable compounds.The production of sodium carbonate through heating (\( \mathrm{NaHCO}_{3} \)) is not only a fascinating chemical change but also a foundational industrial process, providing material for products like glass, detergents, and paper.