Chemical Compound Nomenclature • Part 1: Binary Covalent Compound Nomenclature

Introduction to Chemical Nomenclature
📌 Nomenclature is a system of naming compounds according to IUPAC (International Union for Pure and Applied Chemistry), an international body under the UN.
📌 The purpose of standardized naming is to prevent misinterpretations, as the same compound might be called different names in different regions.
📌 Chemical nomenclature is divided into inorganic and organic compounds; this video focuses only on inorganic nomenclature.

Types of Inorganic Nomenclature Covered
📌 The three types of inorganic nomenclature discussed are: binary covalent compounds, ionic compounds, and hydrates (which will be covered in a future part).
📌 Binary covalent compounds are defined as compounds whose elements consist only of nonmetals and contain only two types of elements (e.g., $\text{CO}_2$).
📌 Ternary compounds (containing three elements, e.g., $\text{C}_2\text{H}_6\text{O}_2$) are excluded from this specific topic.

Rules for Binary Covalent Nomenclature
📌 The order of elements written in the formula follows a strict IUPAC sequence (e.g., $\text{H}$ comes before $\text{O}$ in water, $\text{H}_2\text{O}$, not $\text{OH}_2$).
📌 The name structure is: Name of Element 1 + Name of Element 2 with "-ide" suffix.
📌 If the number of atoms for an element is greater than one, use Greek prefixes (mono, di, tri, tetra, penta, hexa, hepta, octa, nona, deca).
📌 The prefix mono- is not used for the first element in the name (e.g., $\text{CO}_2$ is Carbon dioxide, not Monocarbon dioxide).

Greek Prefixes for Stoichiometry
| Number | Prefix |
| :---: | :---: |
| 1 | mono |
| 2 | di |
| 3 | tri |
| 4 | tetra |
| 5 | penta |
| 6 | hexa |
| 7 | hepta |
| 8 | octa |
| 9 | nona |
| 10 | deca |

Nomenclature Examples and Exceptions
📌 $\text{CO}_2$ is named Carbon dioxide (Carbon (1) + Di-oxide).
📌 $\text{NH}_3$ is named Nitrogen trihydride according to IUPAC rules (Nitrogen (1) + Tri-hydride), but is commonly known as Ammonia.
📌 $\text{H}_2\text{O}$ is systematically named Dihydrogen monoxide, but is almost universally called Water.
📌 $\text{CH}_4$ is systematically named Carbon tetrahydride but is commonly known as Methane (an organic compound name).

Translating Names to Chemical Formulas
📌 To convert a name to a formula, identify the element symbols and use the Greek prefixes to determine the subscripts.
📌 Example: Silicon tetrachloride ($\text{SiCl}_4$) – Silicon (no prefix = 1) and Tetra-chloride (4 Chlorine atoms).
📌 Example: Dinitrogen pentaoxide ($\text{N}_2\text{O}_5$) – Di-nitrogen (2 N atoms) and Penta-oxide (5 O atoms).

Key Points & Insights
➡️ Memorizing the IUPAC order for writing elements in binary covalent compounds is crucial for correct formula representation (e.g., $\text{N}$ before $\text{H}$ in $\text{NH}_3$).
➡️ Be aware of common exceptions like Water ($\text{H}_2\text{O}$), Ammonia ($\text{NH}_3$), and Methane ($\text{CH}_4$), whose common names supersede their strict IUPAC binary covalent names.
➡️ Proficiency requires knowing the names corresponding to chemical symbols ($\text{B}$=Boron, $\text{Si}$=Silicon, $\text{S}$=Sulfur, $\text{Cl}$=Chlorine, etc.) and the Greek numerical prefixes (mono- to deca-).

📸 Video summarized with SummaryTube.com on Feb 05, 2026, 06:27 UTC