Question

Nitrates of all metals are (a) unstable (b) coloured (c) insoluble in water (d) soluble in water

Short answer

Nitrates of all metals are soluble in water.

Step-by-step solution

Understanding Nitrates

Nitrates are the salts or esters of nitric acid, and they are molecules containing the nitrate ion, \( \text{NO}_3^- \). Nitrates are widely present in nature and numerous industrial processes.

Reviewing Nitrate Solubility

A fundamental property of nitrates is their solubility in water. Most metal nitrates are very soluble in water, making this a critical point in understanding their chemical behavior.

Eliminating Incorrect Options

Based on the knowledge that nitrates are generally soluble in water, we can eliminate options (a) unstable, (b) coloured, and (c) insoluble in water as pertinent properties for all metal nitrates.

Identifying the Correct Answer

The correct property that applies to all metal nitrates is (d) soluble in water, as this is a characteristic trait shared by nearly all metal nitrates, regardless of their specific metal ion.

Key concepts

Nitrate ion

The nitrate ion, represented chemically as \( \text{NO}_3^- \), is a polyatomic ion commonly found in various chemical compounds known as nitrates. It consists of one nitrogen atom centrally bonded to three oxygen atoms, forming a trigonal planar structure. This geometric arrangement allows the nitrate ion to be highly stable in many environments.

Because of its negative charge, the nitrate ion can readily combine with metal cations to form nitrates. These compounds are incredibly significant both in nature and in industrial applications.

• In agriculture, nitrates serve as vital nutrients that aid plant growth and development.
• Their stability and reactivity make them useful in explosives and fertilizers.

Understanding the structure and behavior of the nitrate ion is crucial for comprehending the wider class of nitrate compounds.

Metal nitrates

Metal nitrates are formed when metal ions bond with the nitrate ion \( \text{NO}_3^- \). This bonding results in salts that have a variety of uses due to their generally high solubility in water.

Almost all metal nitrates dissolve easily in water, leading to their widespread usage in the chemical industry. They can often be synthesized by direct reaction between a metal or its oxide and nitric acid. Metal nitrates play significant roles in several sectors:

• In the laboratory, they are used for syntheses and as oxidizing agents.
• Industrially, they are crucial in processes like metal finishing and pigment production.

The ability of metal nitrates to dissolve and react makes them immensely valuable for various chemical formulations.

Properties of nitrates

Nitrates possess several notable properties. Most importantly, their solubility in water and crystalline nature make them versatile and predictable in chemical reactions. Here are a few key properties:

• Solubility: Nitrates are universally known for their high solubility in water.
• Color: While most nitrate salts are white or colorless, some can exhibit colors if they incorporate metal ions with distinctive colors.
• Stability: Nitrates are typically stable under normal environmental conditions but can decompose under intense heat, sometimes releasing gases like nitrogen dioxide.

Understanding these properties helps predict how these compounds might behave in different contexts.

Water solubility of salts

The solubility of salts in water is a core property that influences their application and utility. For nitrates, this is especially relevant as their high water solubility distinguishes them from many other salt types.

When dissolved in water, nitrates dissociate into their constituent ions, which can then participate in further chemical reactions. This dissociation is important in:

• Chemistry, where soluble nitrates are used to facilitate reactions in aqueous solutions.
• Biology, where the solubility of nutrient nitrates is essential for life processes involving plant growth.

In general, the solubility of nitrates in water makes them easy to handle and apply, ensuring their continued importance in various scientific and industrial fields.