Problem 70 - Chemistry: The Central Science

Question

Provide the name or chemical formula, as appropriate, for each of the following acids: (a) hydrobromic acid, (b) hydrosulfuric acid, (c) nitrous acid, (d) \(\mathrm{H}_{2} \mathrm{CO}_{3}\), (e) \(\mathrm{HClO}_{3}\), (f) \(\mathrm{HC}_{2} \mathrm{H}_{3} \mathrm{O}_{2}\).

Step-by-Step Solution

Answer

(a) Hydrobromic acid: \(\mathrm{HBr}\) (b) Hydrosulfuric acid: \(\mathrm{H}_{2}\mathrm{S}\) (c) Nitrous acid: \(\mathrm{HNO}_{2}\) (d) \(\mathrm{H}_{2} \mathrm{CO}_{3}\): Carbonic acid (e) \(\mathrm{HClO}_{3}\): Chloric acid (f) \(\mathrm{HC}_{2} \mathrm{H}_{3} \mathrm{O}_{2}\): Acetic acid

Step 1: (a) hydrobromic acid

Hydrobromic acid is a binary acid, which is derived from hydrogen (H) and a non-metal element. In this case, the non-metal is bromine (Br). The chemical formula for hydrobromic acid is simply a combination of these elements: \(\mathrm{HBr}\).

Step 2: (b) hydrosulfuric acid

Hydrosulfuric acid is another binary acid, derived from hydrogen (H) and the non-metal element sulfur (S). The chemical formula for hydrosulfuric acid is \(\mathrm{H}_{2}\mathrm{S}\), reflecting the combination of hydrogen and sulfur in the compound.

Step 3: (c) nitrous acid

Nitrous acid is an oxoacid, which contains hydrogen, oxygen, and another element – in this case, nitrogen. Oxoacids generally have the formula HXOₙ. Nitrous acid has one less oxygen atom than its corresponding anion, nitrate (\(\mathrm{NO}_3^-\)). The chemical formula for nitrous acid is \(\mathrm{HNO}_{2}\).

Step 4: (d) \(\mathrm{H}_{2} \mathrm{CO}_{3}\)

The chemical formula given is for an oxoacid that contains hydrogen, carbon, and oxygen. Based on the formula, this is carbonic acid, with hydrogen, carbon, and oxygen in the appropriate proportions.

Step 5: (e) \(\mathrm{HClO}_{3}\)

The chemical formula provided is an oxoacid containing hydrogen, chlorine, and oxygen. The corresponding anion is chlorate (\(\mathrm{ClO}_3^-\)). This acid is called chloric acid, with hydrogen, chlorine, and oxygen in the right proportions.

Step 6: (f) \(\mathrm{HC}_{2} \mathrm{H}_{3} \mathrm{O}_{2}\)

The given chemical formula consists of hydrogen, carbon, and oxygen. This compound's anion is acetate (\(\mathrm{C}_{2}\mathrm{H}_{3}\mathrm{O}_{2}^-\)). The corresponding acid is acetic acid, which has the chemical formula \(\mathrm{HC}_{2}\mathrm{H}_{3}\mathrm{O}_{2}\).

Key Concepts

Chemical Formulas

Chemical formulas are fundamental in chemistry. They provide a clear and concise way to represent chemical compounds. These formulas show the elements present, using their symbols from the periodic table, as well as the number of each type of atom in a molecule.
For example, the chemical formula for water is \( \text{H}_2\text{O} \), indicating two hydrogen atoms and one oxygen atom.
Knowing chemical formulas helps us understand the composition and structure of substances.To write a chemical formula correctly, it is important to:

• Identify the elements present.
• Determine the correct subscripts to show the number of each atom.
• Use standard symbols from the periodic table.

Understanding these principles is key to mastering acid nomenclature.

Binary Acids

Binary acids are a type of acid made up of hydrogen and one other non-metal element. They are some of the simplest types of acids to memorize because they are composed of just two elements.
Their chemical formula always begins with hydrogen (H). Some examples include:

• Hydrobromic acid (HBr) - composed of hydrogen and bromine.
• Hydrosulfuric acid (H₂S) - composed of hydrogen and sulfur.

Their names typically start with the prefix 'hydro-', followed by the name of the non-metal element with an '-ic' suffix, illustrating their binary nature. Recognizing binary acids can be straightforward if you remember these naming conventions.

Oxoacids

Oxoacids are acids that contain hydrogen, oxygen, and another element, often a non-metal. Unlike binary acids, oxoacids include oxygen in their structures.
They are named based on the non-metal, with suffixes '-ous' for acids with fewer oxygen atoms and '-ic' for those with more. Common examples include:

• Nitrous acid (HNO₂) - with nitrogen and indicatively fewer oxygens than nitric acid (HNO₃).
• Chloric acid (HClO₃) - where the chlorine is bonded with three oxygens.

Oxoacids derive their names from the number of oxygen atoms present and the oxidation state of the central non-metal element.
Mastering how to differentiate and name oxoacids is essential for understanding their chemical behavior.

Acid Names

The names of acids provide key insights into their chemical structure and composition. Understanding acid names helps bridge the gap between chemical formulas and their properties.
Key rules for naming acids include identifying whether an acid is binary or an oxoacid. Here's a quick guide:

• Binary acids start with 'hydro-' and end with '-ic', like hydrobromic acid for HBr.
• Oxoacids ending in '-ic' often have more oxygens (e.g., chloric acid, HClO₃) than those ending in '-ous' (e.g., nitrous acid, HNO₂).
• Some acids, like acetic acid (HC₂H₃O₂), are named based on their functional group or historical name.

Familiarizing yourself with these patterns in naming will assist in interpreting chemical formulas effectively.

Inorganic Chemistry

Inorganic chemistry deals with compounds that mostly do not contain carbon-hydrogen bonds, differentiating them from organic compounds.
Much of inorganic chemistry focuses on the study of metals, minerals, and non-metallic elements. This field includes a wide variety of substances, such as salts, oxides, and, importantly, acids. Key aspects include:

• Understanding the behavior of ions and ionic compounds.
• Studying the reactivity of metals and non-metals.
• Learning about different types of bonds, like ionic and covalent bonds.

Inorganic acids, such as those discussed in this article, are central to many reactions and processes in this branch.
A solid grasp of inorganic chemistry fundamentals facilitates a deeper comprehension of material properties and reactions.