Question

Supply an appropriate name for each of the following: (a) \(\mathrm{HPO}_{4}^{2-} ;\) (b) \(\mathrm{Ca}_{2} \mathrm{P}_{2} \mathrm{O}_{7} ;\) (c) \(\mathrm{H}_{6} \mathrm{P}_{4} \mathrm{O}_{13}\).

Short answer

(a) Hydrogen phosphate ion (b) Calcium pyrophosphate (c) Hexahydrogen tetraphosphate

Step-by-step solution

Interpreting the first chemical formula

The first given chemical formula is \( \mathrm{HPO}_{4}^{2-} \). This is a polyatomic ion, made up of one hydrogen atom (H), one phosphorus atom (P), and four oxygen atoms (O). The \(2-\) indicates that this ion carries a 2- charge. In nomenclature, this compound is referred to as the hydrogen phosphate ion.

Interpreting the second chemical formula

The second given chemical formula is \( \mathrm{Ca}_{2} \mathrm{P}_{2} \mathrm{O}_{7} \). This is a compound made up of two calcium atoms (Ca), two phosphorus atoms (P), and seven oxygen atoms (O). In nomenclature, this compound is referred to as calcium pyrophosphate.

Interpreting the third chemical formula

The third given chemical formula is \( \mathrm{H}_{6} \mathrm{P}_{4} \mathrm{O}_{13} \). This compound consists of six hydrogen atoms (H), four phosphorus atoms (P), and thirteen oxygen atoms (O). In nomenclature, this compound is referred to as hexahydrogen tetraphosphate.

Key concepts

Polyatomic Ions

Polyatomic ions are fascinating building blocks of chemistry, combining many atoms into a single charged particle. Unlike monatomic ions, which consist of a single atom, polyatomic ions are composed of two or more atoms. These groups of atoms work together, sharing electrons, to form an ion with a specific charge.
For example, the ion \(\mathrm{HPO}_{4}^{2-}\) is a polyatomic ion. In this atom, the phosphorus and oxygen group carry a 2- charge due to the shared electrons within the structure. Polyatomic ions are named systematically to reflect their composition. They often contain oxygen, and the suffix changes slightly based on the number present.
Understanding these ions is crucial, as they often occur in multiple chemical reactions. They can form when molecules lose or gain protons or electrons, adjusting their charge. Practicing writing out their formulas and names is a great learning step!

Hydrogen Phosphate

Hydrogen phosphate, known by the formula \( \mathrm{HPO}_{4}^{2-} \), is a companion in many biological and chemical processes. It's an intermediate form in the series of phosphate ions, where hydrogen replaces a portion of oxygen's charge.
This ion is significant in biochemistry and chemical equilibria, often part of the buffers that maintain the pH balance in various systems. It forms by the loss of a hydrogen ion from phosphoric acid, contributing to its negative charge. Typically, the name reflects the presence of one hydrogen and its interaction with phosphate, which is practical and descriptive.
Recognizing hydrogen phosphate is useful when trying to understand or predict reactions, especially those involving phosphorous and its derivatives, given its varied applications in scientific research and industry.

Calcium Pyrophosphate

Calcium pyrophosphate is an interesting compound with the chemical formula \( \mathrm{Ca}_{2} \mathrm{P}_{2} \mathrm{O}_{7} \). It's a combination of calcium, phosphorus, and oxygen, held together to form a stable substance. This is a salt made from pyrophosphoric acid.
In everyday life, calcium pyrophosphate is encountered as it plays roles, such as in certain medical contexts. Caution is needed here as some forms of pyrophosphate can result in crystal deposits in joints. From a naming standpoint, 'pyrophosphate' indicates the presence of an additional oxygen molecule linking two phosphoryl groups, hence its naming.

• Pyrophosphate: Represents two phosphorus and seven oxygen atoms.
• Calcium: The metal ion part balancing the structure's overall charge.

Knowing how to name and identify compounds like calcium pyrophosphate helps understand more about their formation and roles.

Hexahydrogen Tetraphosphate

The compound hexahydrogen tetraphosphate, highlighted by its formula \(\mathrm{H}_{6} \mathrm{P}_{4} \mathrm{O}_{13}\), is a mouthful, yet it's a key player in chemical nomenclature. This compound consists of a hefty four atoms of phosphorus and thirteen oxygen atoms, paired with six hydrogen atoms.
Naming such a compound involves noting each part: 'hexa' indicates six hydrogens, while 'tetra' refers to four phosphorus atoms. It's derived from phosphoric acid variations and gives insights into more extensive phosphate chemistry.
Having a good grasp on such names aids in mastering complex chemical reactions, especially those dealing with large molecular assemblies. Hexahydrogen tetraphosphate's configuration is crucial for certain reactions and offers rich chemical biodiversity shaping our materials and industries. Remembering the prefixes and their counts makes it simpler to tackle these intricate formulas.