Definition

Noun: A monobasic acid is an acid that contains only one replaceable hydrogen atom (H⁺ ion) per molecule. This single hydrogen atom can dissociate (separate) in an aqueous solution to donate one proton. The term describes the acid's basicity, which is the number of replaceable hydrogen atoms.

Usage

• The term is used in chemistry to classify and describe acids based on their molecular structure and reactivity.
• It specifies that each molecule of the acid can react with only one molecule of a base in a neutralization reaction to form one salt.

Examples

• Hydrochloric acid (HCl) is a classic example of a monobasic acid.
• In the laboratory, nitric acid (HNO₃) is frequently used as a monobasic acid.
• The student identified the unknown substance as a monobasic acid because it required one equivalent of base for complete neutralization.

Advanced Usage

• Basicity vs. Strength: It is crucial to distinguish between (monobasic, dibasic, tribasic) and (strong or weak). A monobasic acid can be strong (like HCl) or weak (like acetic acid, CH₃COOH).
• Titration: In acid-base titrations, a monobasic acid has one equivalence point, where the moles of base equal the moles of acid.

Variants and Related Words

• Dibasic Acid (n): An acid containing two replaceable hydrogen atoms per molecule (e.g., H₂SO₄).
• Tribasic Acid (n): An acid containing three replaceable hydrogen atoms per molecule (e.g., H₃PO₄).
• Basicity (n): The number of replaceable hydrogen atoms in an acid molecule.

Synonyms

• Monoprotic acid

Antonyms

• Polybasic acid (e.g., dibasic acid, tribasic acid)

Noun

1. an acid containing only one replaceable hydrogen atom per molecule