Problem 37 - A Complete Resource Book in Chemistry for JEE Main

Question

Mercurous ion is represented as (a) \(\mathrm{Hg}^{2+}\) (b) \(\mathrm{Hg}_{2}^{+}\) (c) \(\mathrm{Hg}_{2}{\underline{\phantom{xx}}}^{2+}\) (d) \(\mathrm{Hg}+\mathrm{Hg}^{2+}\)

Step-by-Step Solution

Answer

The correct representation of the mercurous ion is (c) \(\mathrm{Hg}_{2}{\underline{\phantom{xx}}}^{2+}\).

Step 1: Understanding the Mercurous Ion

The mercurous ion consists of two mercury atoms that share a charge of +2. A key term to note is 'mercurous,' which typically indicates the presence of the diatomic ion with a +2 total charge.

Step 2: Analyze Each Option

We need to select the option that correctly represents this mercurous ion. Let's examine each one:(a) \(\mathrm{Hg}^{2+}\) is a single mercury ion with a +2 charge, but not the diatomic form.(b) \(\mathrm{Hg}_{2}^{+}\) represents two mercury atoms with a +1 charge, which is incorrect for the mercurous ion.(c) \(\mathrm{Hg}_{2}{\underline{\phantom{xx}}}^{2+}\) represents two mercury atoms sharing a +2 charge, which is the correct form of a mercurous ion.(d) \(\mathrm{Hg} + \mathrm{Hg}^{2+}\) is an added form of single ions, not a combined diatomic ion.

Step 3: Select the Correct Answer

The correct representation of the mercurous ion is where two mercury atoms together share a +2 charge, which matches option (c), \(\mathrm{Hg}_{2}{\underline{\phantom{xx}}}^{2+}\).

Key Concepts

Diatomic Ion

A diatomic ion is a type of molecule consisting of exactly two atoms that share an electric charge. Diatomic ions can be comprised of the same element, forming a sort of partnership where they share electrons to balance the charge. This creates a stable arrangement despite the charge.

In the case of the mercurous ion, the two mercury atoms come together to share a charge of +2, forming a diatomic ion. This specific ion is represented as \(\mathrm{Hg}_{2}^{2+}\), where the subscript '2' indicates the presence of two mercury atoms bonded together. Understanding this structure helps explain why some ions do not exist in isolation but rather bond in pairs to fulfill specific chemical properties.

Diatomic ions are important in fields like chemistry because they allow scientists to understand how elements behave when they form compounds. By studying these behaviors, chemists can predict the stability and reactivity of different combinations of atoms.

Mercury Chemistry

Mercury, symbolized as Hg, is a fascinating element due to its unique characteristics and behaviors. Unlike most metals, mercury is liquid at room temperature, which opens up various opportunities for its use in different applications. However, its chemistry can be quite complex due to these unique properties.

In mercury chemistry, the element can form multiple types of ions, including the mercurous ion \(\mathrm{Hg}_{2}^{2+}\) and the mercuric ion \(\mathrm{Hg}^{2+}\). These ions highlight mercury's ability to form compounds with varying oxidation states.

• The mercurous ion, \(\mathrm{Hg}_{2}^{2+}\), involves a bond between two mercury atoms sharing a +2 charge.
• The mercuric ion, \(\mathrm{Hg}^{2+}\), involves a single atom with a +2 charge.

Mercury's chemistry is rich and diverse, largely due to its ability to form such distinct chemical compounds. Understanding these ions allows scientists and students alike to understand how mercury interacts within different chemical environments.

Chemical Nomenclature

Chemical nomenclature is the systematic naming of chemical compounds based on their structure and composition. It follows specific rules to ensure that chemical formulas and names are universally understood.

For ions, nomenclature often involves indicating the charge and, in some cases, the number of atoms involved. For instance:

• The term "mercurous" refers to the diatomic mercury ion \(\mathrm{Hg}_{2}^{2+}\), which involves two mercury atoms sharing a +2 charge, as discussed previously.
• "Mercuric" on the other hand, is used for a single mercury ion \(\mathrm{Hg}^{2+}\).

Chemical nomenclature allows scientists to quickly understand the composition and characteristics of a compound simply by its name. Learning the nomenclature system is crucial for anyone studying chemistry, as it equips them with the skills to examine and understand complex chemical interactions.