Covalent Compounds

The Language of Chemistry Chemistry has a language all of its own… Chemistry English Element Symbols Letters Chemical Formulas Words Chemical Equations Sentences Each element symbol starts with a capital letter 2

Covalent Compounds Covalent bond: atoms share electrons so each has a full outer shell of 8 electrons Binary Covalent Compound: compound made from two non-metals that share electrons Non metal Non metal Covalent compound

Covalent Prefixes 1 = mono- 2 = di- 3 = tri- 4 = tetra- 5 = penta- 6 = hexa- 7 = hepta- 8 = octa- 9 = nona- 10 = deca- Two notes: No “mono” on the first element name If oxygen/oxide: do NOT include the final “o” or “a” on the prefix

Covalent Compounds Formula to Name

Covalent Compounds Formula to Name Formulas will have… 2 non-metal elements To name: Name of the first element with the prefix indicating the number of atoms Name of the second element with the prefix indicating the number of atoms and the suffix “ide”

Examples P2O5 SiO

Write the name for the following compounds Practice Write the name for the following compounds 1. CO2 2. N2O4 3. P4O10 4. CO carbon dioxide dinitrogen tetroxide tetraphosphorus decoxide carbon monoxide

Covalent Compounds Name to Formula

Covalent Compounds Name to Formula Names will have… covalent prefixes before the element name To write: Write the symbols of the first and second element Use the covalent prefixes to determine the subscripts of each element (assume the first element is “1” if there is no prefix). Atoms do not form ions when bonding covalently…you DO NOT need to worry about charges with this type! 

Example Dinitrogen Tetroxide

Example 12

Write the formula for the following compounds Practice Write the formula for the following compounds 1. carbon monoxide 2. nitrogen dioxide 3. sulfur tetrachloride CO NO2 SCl4

A Word of Caution… “di” and “bi” do not mean the same thing! di- bi- Stands for “2” in covalent compounds Means there’s a hydrogen in the polyatomic anion Carbon dioxide = CO2 Sodium biphosphate = Na2HPO4

Write the name for the following compounds Let’s Practice CO2 N2O4 P4O10 CO Carbon dioxide Dinitrogen tetraoxide Tetraphosphorus decaoxide Carbon monoxide Example: Write the name for the following compounds

Nomenclature Summary Naming Chemical Formulas Starts with a metal or NH4 Does not contain a metal = Binary Covalent compound 2 capital letters = Binary Ionic More than 2 elements = Polyatomic Ionic

Mixed Practice – Ionic and Covalent Na2O K3PO4 Cu(OH)2 (NH4)2S MgCl2 Example: Write the name for the following compounds

Write the name for the following compounds Mixed Practice Na2O K3PO4 Cu(OH)2 (NH4)2S MgCl2 Sodium oxide Potassium phosphate Copper (II) hydroxide Ammonium sulfide Magnesium chloride Example: Write the name for the following compounds

Nomenclature Summary Writing Chemical Formulas Does not contain covalent prefixes Does contain covalent prefixes = Binary Covalent compound Ends with “-ide” (except hydroxide & cyanide) = Binary Ionic All others = Polyatomic Ionic

Write the following chemical formulas Mixed Practice Magnesium hydroxide Copper (II) nitrate Iron (III) oxide Nitrogen dioxide Sodium bicarbonate Example: Write the following chemical formulas

Write the following chemical formulas Mixed Practice Magnesium hydroxide Copper (II) nitrate Iron (III) oxide Nitrogen dioxide Sodium bicarbonate Mg(OH)2 Cu(NO3)2 Fe2O3 NO2 NaHCO3 Example: Write the following chemical formulas