Problem 94 - A Complete Resource Book in Chemistry for JEE Main

Question

Which of the following oxides of chlorine is obtained by passing dry chlorine over silver chlorate at \(90^{\circ} \mathrm{C} ?\) (a) \(\mathrm{ClO}_{4}\) (b) \(\mathrm{ClO}_{3}\) (c) \(\mathrm{Cl}_{2} \mathrm{O}\) (d) \(\mathrm{ClO}_{2}\)

Step-by-Step Solution

Answer

The oxide obtained is \(\mathrm{ClO}_2\).

Step 1: Understanding the Reaction

The problem asks to identify the oxide of chlorine obtained when dry chlorine is passed over silver chlorate at \(90^{\circ} \mathrm{C}\). This implies a chemical reaction involving chlorine (\( \mathrm{Cl_2} \)) and silver chlorate (\( \mathrm{AgClO_3} \)).

Step 2: Reaction Conditions

When dry chlorine gas is passed over silver chlorate at \(90^{\circ} \mathrm{C}\), the conditions suggest a decomposition process. We want to find which oxide of chlorine forms under these conditions.

Step 3: Decomposition of Silver Chlorate

Silver chlorate \( (\mathrm{AgClO_3}) \) can decompose according to the formula: \[ \mathrm{2AgClO_3 \rightarrow 2AgCl + 3O_2 + ClO_2} \] in the presence of \( \mathrm{Cl_2} \), chlorine dioxide \( \mathrm{ClO_2} \) is expected to form in this decomposition.

Step 4: Identifying the Correct Oxide

From the decomposition reaction, \( \mathrm{ClO_2} \) is produced. Therefore, the oxide of chlorine that is formed is chlorine dioxide.

Key Concepts

Oxides of Chlorine

Chlorine can form several different oxides, each with unique chemical properties and uses. Oxides of chlorine involve bonding between oxygen and chlorine atoms, resulting in compounds with the general formula

• Chlorine monoxide, \( \text{Cl}_2\text{O} \)
• Chlorine dioxide, \( \text{ClO}_2 \)
• Chlorine trioxide, \( \text{ClO}_3 \)
• Chlorine tetroxide, \( \text{ClO}_4 \)

These oxides showcase different oxidation states of chlorine. For example, in chlorine dioxide, chlorine is in an oxidation state of +4. While chlorine monoxide can act as a bleaching agent, chlorine dioxide is often used in water purification due to its strong oxidizing properties. Understanding these oxides helps in predicting the products of chlorine-related reactions.
These compounds play important roles in different industries, from sanitation in water treatment to use as disinfectants in various applications.

Silver Chlorate Decomposition

Silver chlorate, represented chemically as \( \text{AgClO}_3 \), is a salt that can undergo decomposition in certain conditions. Decomposition is a chemical reaction where a single compound breaks down into two or more products. When silver chlorate is subjected to a thermal condition such as heating at \(90^{\circ}\text{C} \) with chlorine gas, it decomposes. The decomposition follows the reaction: \[ 2\text{AgClO}_3 \rightarrow 2\text{AgCl} + 3\text{O}_2 + \text{ClO}_2 \] Through this process, silver chloride, oxygen gas, and chlorine dioxide are formed. This type of reaction is essential in the laboratory to synthesize chlorine dioxide and study its properties.
Decomposing silver chlorate is a straightforward process that showcases how temperature can influence chemical reactions and drive the breakdown of complex compounds into simpler ones.

Chlorine Dioxide Formation

Chlorine dioxide \( \text{ClO}_2 \) is an important chlorine oxide with a wide range of applications, especially in the field of sanitation and disinfection.It is typically formed through the reaction of chlorine and oxygen compounds like silver chlorate — as outlined in the decomposition of \( \text{AgClO}_3 \). When decomposed at \(90^{\circ}\text{C} \) in the presence of dry chlorine gas, chlorine dioxide is among the primary products. Chlorine dioxide is valued for its strong oxidizing properties which make it an effective disinfectant for water treatment systems. It destroys various pathogens and helps in making water safe for consumption. Aside from its sterilization capabilities, it is used in bleaching textiles and paper pulp.
This compound must be handled with care due to its potent oxidizing nature. Understanding its formation helps not only in academic settings but also provides insights on its practical applications in technology and various industries.