Problem 22 - A Complete Resource Book in Chemistry for JEE Main

Question

When \(\mathrm{SiO}_{2}\) is reacted with sodium carbonate, which gas is liberated? (a) \(\mathrm{O}_{2}\) (b) \(\mathrm{O}_{3}\) (c) \(\mathrm{CO}\) (d) \(\mathrm{CO}_{2}\)

Step-by-Step Solution

Answer

The gas liberated is carbon dioxide \((\mathrm{CO}_2)\).

Step 1: Identify Reactants and Products

The reaction between silicon dioxide \((\mathrm{SiO}_{2})\) and sodium carbonate \((\mathrm{Na}_2\mathrm{CO}_3)\) involves common compounds in chemistry. The products formed typically include sodium silicate and a gaseous by-product. To determine the gas, we must identify the complete chemical reaction.

Step 2: Write the Balanced Chemical Equation

The balanced chemical equation for the reaction is:\[\mathrm{SiO}_{2} + \mathrm{Na}_2\mathrm{CO}_3 \rightarrow \mathrm{Na}_2\mathrm{SiO}_3 + \mathrm{CO}_2\]This equation shows that one mole of silicon dioxide reacts with one mole of sodium carbonate to produce sodium silicate and carbon dioxide.

Step 3: Determine the Liberated Gas

Upon examining the balanced equation, we see that carbon dioxide \((\mathrm{CO}_2)\) is released as a gaseous by-product of this reaction. The sodium silicate remains as a solid compound. Thus, the liberated gas is \(\mathrm{CO}_{2}\).

Key Concepts

SiO2 reaction

When silicon dioxide (SiO₂) reacts with sodium carbonate (Na₂CO₃), an interesting and important chemical reaction occurs. Silicon dioxide is a compound commonly found in nature, largely as quartz, and is a key component in glass production. Sodium carbonate, also referred to as washing soda, is often used in cleaning products and for softening water. When these two substances interact, the silicon dioxide and sodium carbonate undergo a transformation.
In the described reaction, the silicon dioxide combines with sodium carbonate to form sodium silicate (Na₂SiO₃) and carbon dioxide (CO₂) gas. The presence of sodium silicate can be noted as a formation of a solid substance, while the carbon dioxide is a gas that escapes the reaction mixture. Understanding this reaction is crucial because it involves the exchange of particular components that transform into entirely different materials, showcasing the power of chemical interactions.
Thus, SiO₂ reacting with Na₂CO₃ provides insightful examples of chemical reactivity and product formation that are foundational concepts in chemistry.

CO2 liberation

In the realm of chemical reactions, gas formation is an observable and critical outcome, particularly with the liberation of carbon dioxide (CO₂). In the specific reaction between silicon dioxide (SiO₂) and sodium carbonate (Na₂CO₃), carbon dioxide is liberated as a gaseous by-product. This liberation process can be visually confirmed if the reaction is conducted in a partially open system where gas release leads to bubbling or effervescence.
Carbon dioxide liberation can be explained through the decomposition of the carbonate ion. During the reaction, sodium carbonate breaks down, its carbonate component decomposing and releasing CO₂ gas. This release is crucial because CO₂ is a common by-product in various chemical processes.
Recognizing CO₂ liberation helps highlight the importance of monitoring and controlling gaseous emissions in industrial petrochemical processes, contributing to environmental sustainability and compliance.

balanced chemical equation

The balanced chemical equation is central to understanding the stoichiometry of reactions. For the reaction of SiO₂ with Na₂CO₃, the balanced chemical equation is given as:\[\text{SiO}_2 + \text{Na}_2\text{CO}_3 \rightarrow \text{Na}_2\text{SiO}_3 + \text{CO}_2\]Balancing this equation ensures that the law of conservation of mass holds, meaning the mass of reactants equals the mass of products. In our equation, every type of atom is accounted for and equal on both sides, ensuring no discrepancy between the amount of starting materials and their resulting products.
To balance an equation, each component must be adjusted, if needed, so that the number of atoms for each element involved in the reaction is the same on both sides of the equation. A crucial step in many chemistry problems, this balance not only aids in accurately predicting the outcomes of chemical reactions, such as the quantities of products formed, but also in verifying that reactions proceed correctly according to theoretical expectations.
Learning to write and interpret balanced chemical equations is fundamental, enhancing understanding and communication of various chemical reactions' dynamics.