Question

Which one is metaboric acid? (a) \(\mathrm{B}(\mathrm{OH})_{3}\) (b) \(\mathrm{H}_{3} \mathrm{BO}_{3}\) (c) \(\mathrm{H}_{2} \mathrm{~B}_{4} \mathrm{O}_{7}\) (d) \(\mathrm{HBO}_{2}\)

Short answer

The metaboric acid is (d) \( \mathrm{HBO}_2 \).

Step-by-step solution

Identifying Metaboric Acid

Metaboric acid is a type of boric acid with the chemical formula \( ext{HBO}_2 \). It differs from other forms of boric acid such as orthoboric acid \( ext{H}_3 ext{BO}_3 \) and tetraboric acid \( ext{H}_2 ext{B}_4 ext{O}_7 \).

Evaluating the Options

Now, examine the given options. We need to identify which formula corresponds to metaboric acid:- (a) \( ext{B(OH)}_3 \) matches orthoboric acid- (b) \( ext{H}_3 ext{BO}_3 \) is orthoboric acid- (c) \( ext{H}_2 ext{B}_4 ext{O}_7 \) refers to tetraboric acid- (d) \( ext{HBO}_2 \) corresponds to metaboric acid.

Selecting the Correct Option

The chemical formula \( ext{HBO}_2 \) correctly represents metaboric acid. Therefore, option (d) is the correct answer.

Key concepts

Boric Acid Types

Boric acid is a fascinating compound with several variants, each with a unique chemical structure and formula. These different forms occur due to the way the elements in boric acid rearrange, leading to different types like orthoboric, metaboric, and tetraboric acids.

• **Orthoboric Acid**: This is the most commonly encountered form, represented by the chemical formula \( \mathrm{H}_3 \mathrm{BO}_3 \). It's often simply referred to as boric acid and is a weak monobasic Lewis acid.
• **Metaboric Acid**: With the formula \( \mathrm{HBO}_2 \), metaboric acid is formed when orthoboric acid loses a water molecule through condensation. It is typically encountered in crystalline form.
• **Tetraboric Acid**: Also known as pyroboric acid, its formula is \( \mathrm{H}_2 \mathrm{~B}_4 \mathrm{O}_7 \). This type is essentially a more condensed version involving four boron atoms.

Each type exhibits distinct chemical behavior and reactivity, providing diverse utility across various scientific and industrial applications. Understanding these differences is key to identifying which boric acid type suits specific reactions or processes.

Chemical Formulas

Chemical formulas are a concise way of expressing the types and numbers of atoms in a molecule. They are essential tools for scientists and students alike. For boric acids, each type has a precise formula that indicates its unique structure.

• For orthoboric acid, the chemical formula is \( \mathrm{H}_3 \mathrm{BO}_3 \), meaning it contains three hydrogen, one boron, and three oxygen atoms.
• Metaboric acid's chemical formula is \( \mathrm{HBO}_2 \). Notice how it has less hydrogen relative to oxygen, indicating a loss of water from its orthoboric precursor.
• The chemical formula \( \mathrm{H}_2 \mathrm{~B}_4 \mathrm{O}_7 \) for tetraboric acid shows its more complex structure involving multiple boron atoms.

Mastering how to read and write these formulas is foundational in chemistry as it allows one to predict the molecular behavior and reactions that these compounds might undergo.

Inorganic Chemistry

Inorganic chemistry is the branch of chemistry dealing with inorganic compounds, which includes the study of structures, reactivity, and properties of compounds mainly without carbon. Boric acids, being such inorganic compounds, are an excellent subject of study.
Boric acids offer insight into the rich chemistry of non-organic substances, with boron playing a central role. Their interactions with other elements reveal patterns and trends essential for predicting reactions.

• Inorganic compounds like boric acids often form through condensation reactions, where water molecules are eliminated, forming different structural variants.
• The study of these acids contributes to understanding broader concepts in inorganic chemistry, such as acid-base reactions, coordination chemistry, and thermodynamics.

Boric acids underscore the complexity and beauty of inorganic chemistry, manifesting in numerous practical applications from glassmaking to semiconductors.

Acid Identification

Identifying acids involves recognizing their formulas and understanding their reactivity. Inorganic acids like boric acids provide a framework for identifying and categorizing acids based on their chemical compositions and behaviors.

• By examining the chemical formula, one can identify the distinct types of boric acids. This involves recognizing patterns such as the ratio of hydrogen to oxygen atoms.
• Metaboric acid, for instance, is identified by its specific formula, \( \mathrm{HBO}_2 \), which signifies a particular condensation reaction.
• Understanding the structural differences among boric acids helps in predicting their behavior in various chemical reactions, crucial for applications ranging from industrial processing to research labs.

Effective acid identification is a necessary skill in chemistry, facilitating the selection of appropriate chemicals for synthesizing desired products or conducting experiments within safe and controlled parameters.