Question

Give the name or chemical formula, as appropriate, for each of the following acids: \((\mathbf{a}) \mathrm{HBrO}_{3},(\mathbf{b}) \mathrm{HBr},(\mathbf{c}) \mathrm{H}_{3} \mathrm{PO}_{4},(\mathbf{d})\) hypochlorous acid, \((\mathbf{e})\) iodic acid, \((\mathbf{f})\) sulfurous acid.

Short answer

(a) Bromic acid, (b) Hydrobromic acid, (c) Phosphoric acid, (d) HClO, (e) HIO3, (f) H2SO3.

Step-by-step solution

Identify the Compound

We need to recognize the chemical formula for each compound and determine the corresponding name or formula based on IUPAC nomenclature rules.

Name HBrO3

The compound \( \mathrm{HBrO}_3 \) is named based on its oxoacid structure. For this oxoacid, 'bromic' corresponds to the 'ate' anion \( \mathrm{BrO}_3^- \). Therefore, \( \mathrm{HBrO}_3 \) is called bromic acid.

Name HBr

The compound \( \mathrm{HBr} \) is a binary acid, composed of hydrogen and bromine. In aqueous conditions, it is known as hydrobromic acid.

Name H3PO4

\( \mathrm{H}_3 \mathrm{PO}_4 \) is a common oxoacid with the 'phosphoric' corresponding to the 'ate' anion \( \mathrm{PO}_4^{3-} \). Therefore, \( \mathrm{H}_3 \mathrm{PO}_4 \) is phosphoric acid.

Formula for Hypochlorous acid

Hypochlorous acid is a simple oxoacid with the formula \( \mathrm{HClO} \). It derives from the hypochlorite ion \( \mathrm{ClO}^- \).

Formula for Iodic Acid

Iodic acid is an oxoacid with the formula \( \mathrm{HIO}_3 \). It corresponds to the iodate anion \( \mathrm{IO}_3^- \).

Formula for Sulfurous Acid

Sulfurous acid is an oxoacid formula \( \mathrm{H}_2 \mathrm{SO}_3 \), coming from the sulfite ion \( \mathrm{SO}_3^{2-} \).

Key concepts

IUPAC Nomenclature

The International Union of Pure and Applied Chemistry (IUPAC) has established systematic methods for naming chemical compounds. This ensures that everyone in the scientific community can understand chemical names unambiguously.

• IUPAC names are derived based on the structure of the molecules and the constituent ions.
• Consistent naming rules help in predicting the chemical composition and properties of substances.

For acids, the rules vary slightly depending on whether the acid is binary or contains additional oxygen atoms (oxoacids). Understanding IUPAC nomenclature is fundamental when dealing with acids and helps in accurately representing and interpreting chemical reactions.

Oxoacids

Oxoacids are a class of acids that contain oxygen, hydrogen, and another element. Their names usually derive from the polyatomic anion they form when dissolved in water.

• If the anion name ends in '-ate', the corresponding acid name ends in '-ic'. For example, the anion \( \mathrm{SO}_4^{2-} \) (sulfate), corresponds to sulfuric acid \( \mathrm{H}_2\mathrm{SO}_4 \).
• Conversely, if the anion ends in '-ite', the acid ends in '-ous'. An example is the anion \( \mathrm{SO}_3^{2-} \) (sulfite), forming sulfurous acid \( \mathrm{H}_2\mathrm{SO}_3 \).

Understanding the relationship between the anion and the acid name is key to mastering acid nomenclature.

Binary Acids

Binary acids are composed of hydrogen and one other nonmetal element. These acids are usually gaseous in pure form, but when dissolved in water, they form acidic solutions.

• The naming rule for binary acids is simple: start with 'hydro-', followed by the root name of the nonmetal, and end with '-ic acid'.
• For example, \( \mathrm{HCl} \) becomes hydrochloric acid, and \( \mathrm{HBr} \) becomes hydrobromic acid when dissolved in water.

This naming convention helps differentiate binary acids from other types of acids, simplifying the process of identifying them in chemical equations and experiments.

Anion Identification

Understanding anions is essential for identifying and naming acids. Anions are negatively charged ions that form when elements gain electrons.

• In the context of acids, anions often dictate the name of the acid itself.
• For oxoacids, the name of the acid is often derived from its corresponding anion. For instance, bromate \( \mathrm{BrO}_3^- \) converts to bromic acid \( \mathrm{HBrO}_3 \).

Anion identification is a critical skill in chemistry, as it not only aids in naming acids correctly but also in understanding their chemical behavior. Recognizing the different anions helps predict the formation of various acid types and their reactive properties.