Question

Which of the following is a highly corrosive salt? (a) \(\mathrm{FeCl}_{2}\) (b) \(\mathrm{HgCl}_{2}\) (c) \(\mathrm{PbCl}_{2}\) (d) \(\mathrm{Hg}_{2} \mathrm{Cl}_{2}\)

Short answer

The highly corrosive salt is HgCl₂ (mercuric chloride).

Step-by-step solution

Understanding Corrosiveness

Corrosiveness in a salt refers to its ability to corrode materials, often due to its chemical nature and reactions. Common corrosive salts are typically strong acids or bases or have toxic and reactive properties.

Analyzing the Options

We need to analyze each compound to determine its chemical properties: - 8HgCl_{2}d is known as mercuric chloride and is highly toxic and can be corrosive. - cFeCl_{2}, PbCl_{2}, and Hg_{2}Cl_{2}d do not exhibit the same level of corrosiveness.

Evaluating the Corrosive-Type Criteria

To assess corrosiveness, consider toxicity, solubility, and ability to react with metals or organics. eHgCl_{2}d has significant historical and industrial contexts showing it as highly corrosive and toxic.

Making the Final Decision

Based on the corrosive properties discussed, eHgCl_{2}d fits the description of a highly corrosive salt due to its known effects and chemical activity.

Key concepts

Chemical Properties

Chemical properties are essential characteristics that define how a substance behaves in a chemical reaction. When discussing corrosive salts like mercuric chloride (HgCl_{2}), these properties tell us a lot about their potential risks and applications.

• **Ionic Structure**: Many salts are ionic, which means they consist of positively charged ions and negatively charged ions. For example, in HgCl_{2}, mercury forms cations, and chlorine forms anions.
• **Acidity/Basicity**: Corrosive salts often originate from strong acids like hydrochloric acid, which gives them the ability to eat away metals or organic tissue.
• **Thermal Stability**: Some salts decompose at high temperatures, affecting their safety in various applications.

Understanding these chemical properties helps chemists predict how these salts might behave in different environments. For safety, industries study these properties closely to handle salts like HgCl_{2} responsibly.

Toxicity

Toxicity refers to the degree to which a substance can harm humans or animals.

• **Poisonous Nature**: HgCl_{2} is incredibly toxic, making it dangerous even in small quantities. It can be fatal if ingested, inhaled, or absorbed through the skin.
• **Effects on Health**: Exposure can lead to severe health problems like kidney damage, digestive issues, and neurological problems.
• **Environmental Impact**: Besides affecting human health, toxic salts can contaminate soil and water, harming wildlife and ecosystems.

Due to its high toxicity, any interaction with mercuric chloride should be handled with extreme caution. Proper protective gear and protocols are essential in workplaces where such substances are present.

Reactivity

Reactivity explains how a chemical substance interacts with other substances. A highly corrosive and reactive salt like HgCl_{2} can engage in various chemical reactions, often resulting in damage or dangerous compounds.

• **Reaction with Metals**: Corrosive salts can aggressively react with metals, leading to metal damage or dissolution.
• **Organic Material Interaction**: These salts can also severely harm organic tissues, which is why they are often used in low concentrations as a disinfectant.
• **Formation of New Compounds**: Reactive substances might form new and sometimes more dangerous compounds when they interact with other chemicals.

Understanding the reactivity of such salts is crucial, especially in industrial and laboratory settings, to prevent unwanted chemical reactions that could lead to accidents.

Solubility

Solubility is the ability of a substance to dissolve in a solvent, like water. HgCl_{2} has unique solubility characteristics that affect its usage and risk.

• **Water Solubility**: Mercuric chloride is soluble in water, allowing it to spread quickly in aquatic environments. This can be dangerous, as it contaminates water sources rapidly.
• **Temperature Influence**: The solubility of salts can change with temperature. HgCl_{2}'s solubility increases with temperature, potentially elevating its corrosive impact.
• **Solubility in Other Solvents**: It dissolves in various solvents, increasing its versatility but also its risk if mishandled.

With the knowledge of solubility, professionals can better anticipate how these salts behave in different environments, helping in effective containment or neutralization of the hazards.