Naming and Writing Chemical Formulas PDF

CHEMICAL FORMULA  Recall CHEM110 Adecer, Jhoanne Fe C. A charged molecule  ion ex. CN – CHEM110 Adecer, Jhoanne Fe C.  Negative ion CHEM110 Adecer, Jhoanne Fe C.  anion...

CHEMICAL FORMULA  Recall CHEM110 Adecer, Jhoanne Fe C. A charged molecule  ion ex. CN – CHEM110 Adecer, Jhoanne Fe C.  Negative ion CHEM110 Adecer, Jhoanne Fe C.  anion ex. O2- CHEM110 Adecer, Jhoanne Fe C.  Common Polyatomic ions CHEM110 Adecer, Jhoanne Fe C.  Common Polyatomic ions CHEM110 Adecer, Jhoanne Fe C.  Common Polyatomic ions CHEM110 Adecer, Jhoanne Fe C.  Common Polyatomic ions CHEM110 Adecer, Jhoanne Fe C.  Common Polyatomic ions CHEM110 Adecer, Jhoanne Fe C.  Common Polyatomic ions CHEM110 Adecer, Jhoanne Fe C.  Common Polyatomic ions CHEM110 Adecer, Jhoanne Fe C.  Polyatomic Ions Definition tightly bound groups of atoms that behave as a unit (a group) and carry a charge. Examples: SO32-, NO2-, ClO2-  Polyatomic Ions Definition tightly bound groups of atoms that behave as a unit (a group) and carry a charge. Examples: SO32-, NO2-, ClO2- sulfite nitrite chlorite  Molecular Ionic compound compound Can both be represented by a chemical formula.  a chemical formula is a representation of the atoms of elements in a molecular or ionic compound.  CHEMICAL FORMULAS Molecular formula Empirical formula Structural formula  H2O2 What can we get from a CHEM110 Adecer, Jhoanne Fe C. molecular formula?  exact number of atoms of the elements in one specific compound. CHEM110 Adecer, Jhoanne Fe C. Example 1: Name: hydrogen peroxide Molecular Formula: H2O2 Name: hydrogen peroxide Molecular Formula: H2O2 Empirical Formula: HO  HO What can we get from an CHEM110 Adecer, Jhoanne Fe C. empirical formula?  Simplest whole number ratio of atoms of the elements in a compound. CHEM110 Adecer, Jhoanne Fe C. H2O2 Structural Formula: Structural Formula: Shows a graphic representation, giving the number of atoms and the arrangement of atoms in a compound. Naming Compounds  MOLECULAR COMPOUNDS composed of molecules in which elements share electrons (covalent bonding). usually composed of 2 nonmetals.  Molecular Compounds Examples CS2 SiO2 BF3  BINARY MOLECULAR COMPOUNDS Binary means 2 elements Molecular means composed of nonmetals NO ionic charges are present  NAMING BINARY MOLECULAR COMPOUNDS Prefixes are used to show how many atoms are present in each molecule.  Covalent Prefixes Mono (or no prefix) – 1 Hexa – 6 Di – 2 Hepta – 7 Tri – 3 Octa – 8 Tetra – 4 Nona – 9 Penta – 5 Deca – 10  NAMING BINARY MOLECULAR COMPOUNDS CO2 —> carbon dioxide no mono prefix is used on first element Di means 2 oxygen atoms!!  NAMING BINARY MOLECULAR COMPOUNDS (prefix + element root + ide) i.e.PCl3 phosphorous trichloride All binary compounds end in -ide!!! N2 O N2 O dinitrogen monoxide  IONIC COMPOUNDS Examples NaCl CaBr2 KI  IONIC CHARGES Group IA -> 1+ Group II A -> 2+ Charges in “Group A elements” are numerically equal to their group number.  IONIC CHARGES Group IA -> 1+ Cations formed from metals have Group II A -> 2+ the same name as the metals. Ex. Lithium ion  IONIC CHARGES Group VA -> 3- Elements in groups 4A and 8A rarely Group VI A -> 2- form compounds. Group VII A -> 1- Group VIII A -> Noble Gases WRITING CHEMICAL FORMULA FOR IONIC COMPOUNDS If charges cancel, just write the symbols Na+1 Cl-1 NaCl If charges do not cancel, criss-cross: Ca+2 Cl-1 CaCl2 ***Do not write the charge, only the number ***Do not write the 1  BINARY IONIC COMPOUNDS Binary means 2 elements Ionic means a metal and a non-metal (or cation and anion) Writing Formulas charges must balance so compound charge is neutral.  BINARY IONIC COMPOUNDS WritingFormulas from Names 1st word = CATION 2nd word = ANION name with -ide ending.  WRITING CHEMICAL FORMULA FOR BINARY IONIC COMPOUNDS NaBr —> sodium bromide MgF2 —> magnesium fluoride  BINARY IONIC COMPOUNDS potassium chloride K+ Cl- –> KCl aluminum oxide 3+ Al2 O3 2- –> Al2O3 Notice ending of name is -ide!  TERNARY IONIC COMPOUNDS Ternary means 3 different elements Usually contain Polyatomic ions  TERNARY IONIC COMPOUNDS: Writing Formulas Ca2+ CO32- —> CaCO3 Charges canceled. Just write the symbols calcium carbonate  TERNARY IONIC COMPOUNDS: Writing Formulas calcium nitrate —-> Ca+2 (NO3)-1 Notice the charges didn’t Ca(NO3)2 cancel so they criss crossed  Naming with Transition Metals (STOCK SYSTEM) First word = CATION Second word = ANION – The Roman numeral will tell you the charge of the transition metal  Naming with Transition Metals copper (I) oxide Cu+1 O -2 Cu2O  Writing Formulas with Transition Metals FeCl3 iron (III) chloride Fe+3 Cl-1 FeCl2 iron (II) chloride Fe+2 Cl-1 *Reverse criss-cross to know the charge/Roman numeral  Naming with Transition Metals (CLASSICAL SYSTEM) Uses the suffix -ous or -ic. These suffixes represent the lower and higher charges of the ion, respectively.  with Transition Metals FeCl3 ferric chloride Fe+3 Cl-1 FeCl2 ferrous chloride Fe+2 Cl-1 *Reverse criss-cross to know the charge/Roman numeral ANION-CONTAINING ACIDS If the anion ends in “-ide”, the prefix “hydro-” is added, and the anion root word is modified with a suffix “-ic” Example: HCl chloride - hydrochloric acid ANION-CONTAINING ACIDS If the anion contains oxygen, its root word ends in “-ate”, replace “-ate” with “-ic”. Example: H3PO4 phosphate - phosphoric acid ANION-CONTAINING ACIDS If the anion contains oxygen, its root word ends in “-ite”, replace “-ite” with “-ous”. Example: H2SO3 sulfite - sulfurous acid  Book Activity - TechFactor, page 55 table B  Chemical Cation Anion Name Formula Cu3PO4 Mg 2+ OH - lithium acetate SO2