Question

Give the formula for each acid. a) perchloric acid b) hydriodic acid

Short answer

Perchloric acid: HClO₄; Hydriodic acid: HI.

Step-by-step solution

Identify the Acid Type

Perchloric acid is an oxoacid, which means it contains oxygen, while hydriodic acid is a binary acid, containing hydrogen and one other non-metal.

Determine the Chemical Formula for Perchloric Acid

Perchloric acid is derived from perchlorate ion, which is ClO₄⁻. Adding a hydrogen ion (H⁺), which neutralizes the charge, gives the formula for perchloric acid: HClO₄.

Determine the Chemical Formula for Hydriodic Acid

Hydriodic acid comes from hydrogen and iodine atoms. Binary acids typically have the formula HX, where X is a halogen. Therefore, the formula for hydriodic acid is HI.

Key concepts

Oxiacids: Understanding the Basics

Oxiacids are a type of acid that contain oxygen, hydrogen, and another element, typically a non-metal. These acids are also known as oxyacids. An important feature of oxiacids is that their acidic behavior is typically associated with the hydrogen atoms that are bonded to oxygen atoms. This means that the structure of the acid is key to its properties and how it reacts chemically.
To identify an oxiacid, you can look for a chemical formula that includes hydrogen (H), oxygen (O), and another element. Generally, these acids are named using the suffix "-ic" or "-ous", depending on the number of oxygen atoms. Oxiacids play an essential role in both natural and industrial processes.

• Found in natural systems like plant and animal tissues.
• Used in industry for manufacturing chemicals and processing materials.

Understanding oxiacids is foundational in chemistry as they often participate in important reactions.

Binary Acids: Simple yet Powerful

Binary acids are acids composed of hydrogen and one other non-metal element. Unlike oxiacids, they do not contain oxygen. They are typically written in the format HX, where "X" is the non-metal. One of the key aspects of binary acids is that they usually contain non-metal elements from the halogen group.
These acids are named with the prefix "hydro-" followed by the name of the non-metal and the suffix "-ic". For example, hydrochloric acid (HCl) is a binary acid consisting of hydrogen and chlorine. Binary acids are often found in aqueous solutions and are a fundamental topic in acid-base chemistry.

• The strength of a binary acid depends on the bond strength between hydrogen and the non-metal.
• Commonly used in various chemical applications like cleaning and etching metals.

Binary acids are crucial in many chemical reactions and have a wide range of practical uses.

Perchloric Acid: A Strong Oxoacid

Perchloric acid is one of the most powerful oxiacids, known for its strong acidic properties. Its chemical formula is derived from the perchlorate ion (\(ClO_4^-\)) by adding a hydrogen ion (\(H^+\)), resulting in the formula \(HClO_4\). This acid is notable for being highly reactive and is often used in analytical chemistry.
Perchloric acid is characterized by having a high oxidation state of chlorine, which contributes to its strong acidic nature. Although it is a valuable acid in laboratories due to its reactivity, it must be handled with caution because it is corrosive and can become explosive under certain conditions.

• Excellent oxidizing agent used in synthesis and purification processes.
• Widely used to standardize solutions in titrations.

Perchloric acid's powerful properties make it a substance that demands respect and careful handling.

Hydriodic Acid: A Potent Binary Acid

Hydriodic acid is a binary acid with the chemical formula \(HI\), made up of hydrogen and iodine. As with other binary acids, it comprises two elements. The "hydro-" prefix and "-ic" suffix help identify it as an acid. Among the binary acids, hydriodic acid is considered quite strong, especially when dissolved in water.
This acid has a significant role in organic and inorganic chemistry due to its reducing properties. It serves as a reagent in various chemical reactions, particularly where iodine is involved. Its strong acidity makes it effective in breaking down organic compounds.

• Used in pharmaceuticals and as a reducing agent in chemical syntheses.
• Often produced in situ for specific reactions due to its high reactivity.

Understanding hydriodic acid's properties and its applications is crucial for chemists working with strong acids.