Question

Selenium, an element required nutritionally in trace quantities, forms compounds analogous to sulfur. Name the following ions: (a) \(\mathrm{SeO}_{4}^{2-}\), (b) \(\mathrm{Se}^{2-}\), (c) \(\mathrm{HSe}^{-}\), (d) \(\mathrm{HSeO}_{3}^{-}\).

Short answer

The given ions are named as follows: (a) \(\mathrm{SeO}_{4}^{2-}\): selenate (b) \(\mathrm{Se}^{2-}\): selenide (c) \(\mathrm{HSe}^{-}\): hydrogen selenide (biselenide) (d) \(\mathrm{HSeO}_{3}^{-}\): hydrogen selenite (biselenite)

Step-by-step solution

Naming \(\mathrm{SeO}_{4}^{2-}\) ion

First, we will find the name of the \(\mathrm{SeO}_{4}^{2-}\) ion. This ion is very similar to the \(\mathrm{SO}_{4}^{2-}\) ion, which is known as sulfate. Since selenium (Se) is chemically similar to sulfur (S), we can name the \(\mathrm{SeO}_{4}^{2-}\) ion as "selenate."

Naming \(\mathrm{Se}^{2-}\) ion

Next, we find the name of the \(\mathrm{Se}^{2-}\) ion. This ion is analogous to the \(\mathrm{S}^{2-}\) ion, which is known as sulfide. Therefore, we can name the \(\mathrm{Se}^{2-}\) ion as "selenide."

Naming \(\mathrm{HSe}^{-}\) ion

Now, we will find the name of the \(\mathrm{HSe}^{-}\) ion. This ion is similar to the \(\mathrm{HS}^{-}\) ion, which is known as hydrogen sulfide or bisulfide. Thus, we can name the \(\mathrm{HSe}^{-}\) ion as "hydrogen selenide" or "biselenide."

Naming \(\mathrm{HSeO}_{3}^{-}\) ion

Finally, we find the name of the \(\mathrm{HSeO}_{3}^{-}\) ion. It is structurally analogous to the \(\mathrm{HSO}_{3}^{-}\) ion, which is known as hydrogen sulfite or bisulfite. Therefore, we can name the \(\mathrm{HSeO}_{3}^{-}\) ion as "hydrogen selenite" or "biselenite." To sum up, we have named the given ions as follows: (a) \(\mathrm{SeO}_{4}^{2-}\): selenate (b) \(\mathrm{Se}^{2-}\): selenide (c) \(\mathrm{HSe}^{-}\): hydrogen selenide (biselenide) (d) \(\mathrm{HSeO}_{3}^{-}\): hydrogen selenite (biselenite)

Key concepts

Chemical Nomenclature

Chemical nomenclature is a system set by chemists for naming chemical substances. It's vital in chemistry to ensure clarity and consistency. This system allows for the easy identification and communication about specific chemical compounds.Inorganic chemistry, in particular, uses specific rules to name different ions and compounds. These rules help to classify compounds, making them easier to study and talk about. Key rules often involve the identification of functional groups, oxidation states, and the number of atoms.For example, when naming ions like \(\mathrm{SeO}_{4}^{2-}\), one must recognize the similarity to sulfate, which tells us it is a 'selenate'. Understanding the roots of names like "ate", "ite", "ide", and others is crucial in mastering chemical nomenclature.

Selenium Compounds

Selenium, represented by the symbol Se, is a chemical element that shares similarities with sulfur and is vital for some biological processes in trace amounts. Its compounds are similar in structure and reactivity to those of sulfur due to their place in the same group of the periodic table.Selenium forms various ions that are analogous to sulfur compounds, such as:

• Selenate (\(\mathrm{SeO}_{4}^{2-}\)), comparable to sulfate ( \(\mathrm{SO}_{4}^{2-}\)).
• Selenide (\(\mathrm{Se}^{2-}\)), analogous to sulfide (\(\mathrm{S}^{2-}\)).

Learning about these selenium compounds not only aids in chemical naming but also enhances understanding of chemical reactions and properties in the context of biological and environmental systems.

Anion Naming

Anions are negatively charged ions, and naming them correctly is a critical part of chemical nomenclature. Typically, the suffix '-ide' is used for simple anions, such as "selenide" for \(\mathrm{Se}^{2-}\). For compound anions containing oxygen, '-ate' and '-ite' suffixes are frequently used; 'ate' for those with more oxygen atoms and 'ite' for those with fewer.Among selenium anions:

• The \(\mathrm{SeO}_{4}^{2-}\) is called "selenate".
• The \(\mathrm{Se}^{2-}\) is referred to as "selenide".
• The \(\mathrm{HSe}^{-}\) is named as "hydrogen selenide" or "biselenide".
• The \(\mathrm{HSeO}_{3}^{-}\) is known as "hydrogen selenite" or "biselenite".

Mastering anion naming involves memorization and understanding the systematic nature of chemical naming conventions that unify global scientific communication.

Sulfur Analogs

Sulfur analogs are compounds where selenium essentially 'replaces' sulfur. Due to both being in the same group on the periodic table, selenium and sulfur share similar chemical properties, making their compounds analogous.These analogs are evident in the naming conventions, where the structure and formula of a sulfur compound aid in deriving the name of the corresponding selenium compound:

• \(\mathrm{SO}_{4}^{2-}\) is "sulfate", hence \(\mathrm{SeO}_{4}^{2-}\) becomes "selenate".
• \(\mathrm{S}^{2-}\) is "sulfide", thus \(\mathrm{Se}^{2-}\) is "selenide".
• \(\mathrm{HS}^{-}\) is "hydrogen sulfide", making \(\mathrm{HSe}^{-}\) "hydrogen selenide".
• \(\mathrm{HSO}_{3}^{-}\) is "hydrogen sulfite", so \(\mathrm{HSeO}_{3}^{-}\) is termed "hydrogen selenite".

Understanding sulfur analogs allows chemists to predict and describe various properties and reactions of selenium compounds by inferring from known sulfur chemistry.