Chapter Naming & Formula Writing for Molecular Compounds

Molecular Compounds Molecular compounds are those made up of exclusively non-metal atoms. Molecular compounds are those made up of exclusively non-metal atoms. Molecular compounds bond by sharing valence electrons to gain a filled outermost shell. As a result, these are referred to as covalent bonds. Molecular compounds bond by sharing valence electrons to gain a filled outermost shell. As a result, these are referred to as covalent bonds. Common examples include pure oxygen (O 2 ), carbon dioxide (CO 2 ), water (H 2 O) and glucose (C 6 H 12 O 6 ). Common examples include pure oxygen (O 2 ), carbon dioxide (CO 2 ), water (H 2 O) and glucose (C 6 H 12 O 6 ).

The “7” Diatomic Molecules There are seven molecular elements that are frequently found in their natural form as diatomic molecules (two atoms). These are: There are seven molecular elements that are frequently found in their natural form as diatomic molecules (two atoms). These are: I 2 (s) Iodine“I” I 2 (s) Iodine“I” Br 2(l) Bromine “Bring” Br 2(l) Bromine “Bring” Cl 2(g) Chlorine“Clay” Cl 2(g) Chlorine“Clay” F 2(g) Fluorine“For” F 2(g) Fluorine“For” O 2(g) Oxygen “Our” O 2(g) Oxygen “Our” N 2(g) Nitrogen“New” N 2(g) Nitrogen“New” H 2(g) Hydrogen“House” H 2(g) Hydrogen“House”

Naming Binary Molecular Compounds Binary molecular compounds are those that contain two different types of non-metal elements in their molecular formula Binary molecular compounds are those that contain two different types of non-metal elements in their molecular formula e.g. CO, C 3 H 8, NO 2, BF 3, P 4 O 10, etc. e.g. CO, C 3 H 8, NO 2, BF 3, P 4 O 10, etc. To name binary molecular compounds, we must use prefixes to denote how many of each atom appear in the molecular formula To name binary molecular compounds, we must use prefixes to denote how many of each atom appear in the molecular formula

Molecular prefixes The prefixes used in molecular compound nomenclature are: The prefixes used in molecular compound nomenclature are: 1 – mono6 – hexa 2 – di7 – hepta 3 – tri8 – octa 4 – tetra9 – nona 5 – penta10 – deca

Molecular Nomenclature To name binary molecular compounds: To name binary molecular compounds: 1 st atom: prefix* + element name 1 st atom: prefix* + element name 2 nd atom: prefix + element stem + “ide” 2 nd atom: prefix + element stem + “ide” * the prefix “mono” is always omitted for the 1 st atom Try some: Try some: CO 2 CO 2 carbon dioxide carbon dioxide N 2 O N 2 O dinitrogen monoxide dinitrogen monoxide P 4 O 10 P 4 O 10 tetraphosphorus decaoxide tetraphosphorus decaoxide CS 2 CS 2 carbon disulfide carbon disulfide

Molecular Nomenclature Many molecular compounds have common names that have not changed over time such as: Many molecular compounds have common names that have not changed over time such as: H 2 O = water H 2 O = water H 2 O 2 = hydrogen peroxide H 2 O 2 = hydrogen peroxide O 3 = ozone O 3 = ozone CH 4 = methane CH 4 = methane NH 3 = ammonia NH 3 = ammonia

Homework Q. 1-5 p.204. Q. 1-5 p.204. Wksht Wksht