Question

Select the correct statement(s): (a) \(\mathrm{Cl}_{2} \mathrm{O}\) and \(\mathrm{ClO}_{2}\) are used as bleaching agents and as germicides (b) \(\mathrm{ClO}_{2}\) is the anhydride of \(\mathrm{HClO}_{2}\) and \(\mathrm{HClO}_{3}\) (c) \(\mathrm{I}_{2} \mathrm{O}_{5}\) is used in the quantitative estimation of \(\mathrm{CO}\) (d) \(\mathrm{Cl}_{2} \mathrm{O}_{7}\) is anhydride of \(\mathrm{HClO}\)

Short answer

(a) and (c) are correct.

Step-by-step solution

Analyze Statement (a)

Statement (a) suggests that \( \mathrm{Cl}_2 \mathrm{O} \) and \( \mathrm{ClO}_2 \) are used as bleaching agents and germicides. \( \mathrm{Cl}_2 \mathrm{O} \) is indeed used as a bleaching agent, particularly in water treatment, due to its strong oxidizing properties. \( \mathrm{ClO}_2 \) is also used for bleaching (especially in the pulp and paper industry) and as a disinfectant. Therefore, statement (a) is correct.

Evaluate Statement (b)

Statement (b) claims that \( \mathrm{ClO}_2 \) is the anhydride of \( \mathrm{HClO}_2 \) (chlorous acid) and \( \mathrm{HClO}_3 \) (chloric acid). In reality, \( \mathrm{ClO}_2 \) is the anhydride of \( \mathrm{HClO}_2 \) but not \( \mathrm{HClO}_3 \). For an anhydride relationship, the formula typically represents a dehydration or condensation product of the acid. Thus, statement (b) is incorrect.

Analyze Statement (c)

Statement (c) asserts that \( \mathrm{I}_2 \mathrm{O}_5 \) is used in the quantitative estimation of \( \mathrm{CO} \). \( \mathrm{I}_2 \mathrm{O}_5 \) is commonly used to determine the concentration of carbon monoxide in the air. It reacts with carbon monoxide to form \( \mathrm{CO}_2 \) and liberates iodine, which can be titrated. This makes statement (c) correct.

Assess Statement (d)

Statement (d) suggests that \( \mathrm{Cl}_2 \mathrm{O}_7 \) is the anhydride of \( \mathrm{HClO} \) (hypochlorous acid). In fact, \( \mathrm{Cl}_2 \mathrm{O}_7 \) is the anhydride of \( \mathrm{HClO}_4 \) (perchloric acid), not \( \mathrm{HClO} \). An anhydride is formed from the dehydration of an acid with the same valency as the number of oxygen atoms. Thus, statement (d) is incorrect.

Key concepts

Chemical Anhydrides

Chemical anhydrides are compounds formed by the removal of water from an acid. They are often seen as the 'parent' compound of acids when considering the inverse reaction. When an acid loses a water molecule, it can form an anhydride.
A classic example is the relationship between sulfuric acid (H₂SO₄) and its anhydride, sulfur trioxide (SO₃). When sulfuric acid loses a water molecule, it transforms into sulfur trioxide.
An important aspect to remember is that the formation of anhydrides involves acids having similar valency to the number of oxygen atoms in the anhydride. This process is critical in various industrial applications, including the synthesis of other chemicals.

Oxidizing Agents

Oxidizing agents are substances that can accept electrons from another species. They are essential in a wide range of chemical reactions, including combustion, respiration, and corrosion.
These agents facilitate oxidation by gaining electrons themselves while causing another substance to lose electrons. Oxidizing agents are often employed in purification and disinfection processes, such as in water treatment, because of their ability to break down pollutants.
In an industrial context, substances like potassium permanganate and hydrogen peroxide are commonly used oxidizing agents due to their effectiveness and versatility.

Bleaching Agents

Bleaching agents are chemicals commonly used to whiten or lighten the color of materials. They work by breaking down colored compounds into smaller, colorless molecules.
In the paper and textile industries, bleaching agents like chlorine dioxide are widely used to achieve a bright white finish. This compound is particularly favored due to its less damaging nature compared to other bleach options.
Beyond industrial applications, household bleach, typically a solution of sodium hypochlorite, is used for cleaning and disinfecting due to its strong bleaching effect. The effectiveness of bleaching agents largely depends on their oxidizing power to react with colored molecules.

Quantitative Analysis

Quantitative analysis refers to the measurement and calculation of the actual amounts or concentrations of substances using chemical methods. This type of analysis is crucial in fields like pharmaceuticals, environmental science, and food chemistry.
Methods commonly used in quantitative analysis include titration, gravimetric analysis, and spectrophotometry. A practical example is the use of iodine pentoxide ( I₂O₅ ) in determining carbon monoxide levels. It reacts with CO to release iodine, the concentration of which can then be measured through titration.
These techniques are vital for ensuring product safety, compliance with regulations, and maintaining quality standards.

Halogen Oxides

Halogen oxides are compounds formed by halogens (like chlorine, bromine, and iodine) bonded to oxygen. These compounds can have a variety of chemical and physical properties depending on the halogen involved.
Halogen oxides play significant roles in industrial and environmental chemistry. For instance, chlorine dioxide ( ClO₂ ) is extensively used as a bleaching and disinfecting agent, while iodine pentoxide ( I₂O₅ ) finds use in detecting contaminants like CO in the air.
These compounds are prized for their high reactivity, making them suitable for tasks ranging from water purification to the synthesis of other chemical products.