Problem 37 - Chemistry: An Atoms-Focused Approach

Question

Give the name or chemical formula of each of the following acids: (a) HF; (b) \(\mathrm{H}_{2} \mathrm{SO}_{3} ;\) (c) phosphoric acid; (d) nitrous acid.

Step-by-Step Solution

Answer

(a) HF Hydrogen fluoride (HF) is a weak, colorless acid. It is the chemical compound formed between a hydrogen ion and a fluorine ion, creating a polar covalent bond. (b) H\(_2\)SO\(_3\) H\(_2\)SO\(_3\) is known as sulfurous acid. It is a weak, colorless acid and formed by dissolving sulfur dioxide in water. (c) Phosphoric acid Phosphoric acid's chemical formula is H\(_3\)PO\(_4\). It is a colorless, odorless mineral acid that has a syrupy consistency and has a wide range of applications including fertilizer production and food industry. (d) Nitrous acid Nitrous acid's chemical formula is HNO\(_2\). It is a weak, unstable acid with a pale blue color, often used as a reducing agent.

Step 1: (a) HF

Hydrogen fluoride (HF) is a weak, colorless acid. It is the chemical compound formed between a hydrogen ion and a fluorine ion, creating a polar covalent bond.

Step 2: (b) H\(_2\)SO\(_3\)

H\(_2\)SO\(_3\) is known as sulfurous acid. It is a weak, colorless acid and formed by dissolving sulfur dioxide in water.

Step 3: (c) Phosphoric acid

Phosphoric acid's chemical formula is H\(_3\)PO\(_4\). It is a colorless, odorless mineral acid that has a syrupy consistency and has a wide range of applications including fertilizer production and food industry.

Step 4: (d) Nitrous acid

Nitrous acid's chemical formula is HNO\(_2\). It is a weak, unstable acid with a pale blue color, often used as a reducing agent.

Key Concepts

Chemical Formulas

Chemical formulas are a way to represent the components and structure of a compound. Each chemical formula consists of element symbols followed by numbers which indicate the number of atoms of each element in a molecule. For instance, in the formula \( \mathrm{H}_2\mathrm{SO}_3 \) for sulfurous acid, \( \mathrm{H}_2 \) denotes two hydrogen atoms, \( \mathrm{S} \) denotes a single sulfur atom, and \( \mathrm{O}_3 \) signifies three oxygen atoms.
A chemical formula gives insight into the composition and sometimes the molecular structure of the compound as well. Understanding these formulas is crucial for recognizing and predicting chemical behavior.

Weak Acids

Weak acids are acids that do not completely dissociate into their ions in a solution. This means that not all of the acid molecules donate their hydrogen ions, resulting in a higher pH compared to strong acids. For example, sulfurous acid (\( \mathrm{H}_2\mathrm{SO}_3 \)) and hydrogen fluoride (HF) are weak acids.
Characteristics of weak acids include:

• They partially dissociate in water.
• They have higher pH values compared to strong acids.
• They can be involved in equilibrium reactions, partially converting to their respective ions.

Understanding the nature of weak acids is essential in predicting their behavior in various chemical reactions.

Covalent Bonds

Covalent bonds are a type of chemical bond where two atoms share one or more pairs of valence electrons. These bonds typically form between non-metal atoms. A classic example is the bond found in hydrogen fluoride (HF). Here, both hydrogen and fluorine atoms share electrons, creating a link between them.
Covalent bonds can be:

• Polar: Unequal sharing of electrons as seen in HF, resulting in a molecule with a slight positive and negative side.
• Non-polar: Equal sharing of electrons, resulting in a symmetrical distribution of charge.

Covalent bonds are integral in forming the structure of molecules and dictate how they interact with other substances.

Sulfurous Acid

Sulfurous acid is a chemical compound with the formula \( \mathrm{H}_2\mathrm{SO}_3 \). It results from the dissolution of sulfur dioxide (SO\(_2\)) in water. It is categorized as a weak acid and is characterized by its ability to partially dissociate into hydrogen ions and bisulfite ions in solution.
Important points about sulfurous acid:

• It plays a role in acid rain formation when sulfur dioxide is emitted from burning fossil fuels.
• It is used in some industrial processes, such as the manufacture of certain chemicals.

Understanding sulfurous acid is necessary for fields related to environmental science and industrial chemistry.