Compounds

Know Your Periodic Table Transition Metals Metals

Naming Ionic Compounds  Binary Ionic Compounds  Consist of two elements: metal cation and a non-metal anion  Metal is named first and says its own name  Non-metal is named second and changes its suffix to “ide”  For transition metals with more than one ionic charge  Use the anions to determine their charge  Indicate their charge with roman numerals  Only Ag +, Zn 2+, and Cd 2+ have 1 charge. You do not need Roman numerals for these  Binary Ionic Compounds  Consist of two elements: metal cation and a non-metal anion  Metal is named first and says its own name  Non-metal is named second and changes its suffix to “ide”  For transition metals with more than one ionic charge  Use the anions to determine their charge  Indicate their charge with roman numerals  Only Ag +, Zn 2+, and Cd 2+ have 1 charge. You do not need Roman numerals for these

Examples Ions Compound Name Sodium & chlorine Sodium chloride Aluminum & chlorine Aluminum chloride Aluminum & oxygen Aluminum oxide Sodium & sulphur Sodium sulphide Iron (2 +) & Oxygen iron (II) oxide Iron (3+) & Oxygen iron (III) oxide

Formulas for Ionic Compounds  Binary Ionic Compounds  Write down the symbols for each individual ion side by side – cation first, anion second  Balance the charges by crossing them (Swap & Drop)  *Charges become subscripts*  Write the formula  Note:  You do not need to write the subscript 1 in the formula  You should reduce the subscripts if possible  Binary Ionic Compounds  Write down the symbols for each individual ion side by side – cation first, anion second  Balance the charges by crossing them (Swap & Drop)  *Charges become subscripts*  Write the formula  Note:  You do not need to write the subscript 1 in the formula  You should reduce the subscripts if possible

Examples Compound Name IonsFormula Sodium chloride Na + & Cl - NaCl Aluminum oxide Al 3+ & O 2- Al 2 O 3 iron (III) oxide Fe 3+ & O 2- Fe 2 O 3 iron (II) oxide Fe 2+ & O 2- Fe 2 O 2  FeO

Naming Ionic Compounds  Ternary Ionic Compounds  Ionic compounds that contain polyatomic ions  Polyatomic ions act as a single unit (subscripts included)  Monatomic cations say their own name; monatomic anions end in the suffix “ide”  Polyatomic ions always say their own name  When more than one polyatomic ion is used in a formula, it will be placed in brackets  Ternary Ionic Compounds  Ionic compounds that contain polyatomic ions  Polyatomic ions act as a single unit (subscripts included)  Monatomic cations say their own name; monatomic anions end in the suffix “ide”  Polyatomic ions always say their own name  When more than one polyatomic ion is used in a formula, it will be placed in brackets

Examples Ions Compound Name Ammonium & chlorine Ammonium chloride Potassium & sulfate Potassium sulfate Lead (2+) & phosphate Lead (II) phosphate Ammonium & oxalate Ammonium oxalate

Formulas for Ionic Compounds  Ternary Ionic Compounds  Same as binary ionic compounds  Make sure that when you balance the charges that the subscript for a polyatomic ion is OUTSIDE of the brackets  This is because polyatomic ions act as a single unit and the subscript applies to the entire unit  Remember, numbers WITHIN the brackets of a polyatomic ion CANNOT be reduced  Ternary Ionic Compounds  Same as binary ionic compounds  Make sure that when you balance the charges that the subscript for a polyatomic ion is OUTSIDE of the brackets  This is because polyatomic ions act as a single unit and the subscript applies to the entire unit  Remember, numbers WITHIN the brackets of a polyatomic ion CANNOT be reduced

Examples Compound Name IonsFormula Ammonium sulphide NH 4+ & S 2- (NH 4 ) 2 S Potassium carbonate K + & CO 3 2- K 2 CO 3 Iron (II) nitrate Fe 2+ & NO 3 - Fe(NO 3 ) 2 Sodium sulfate Na + & SO 4 2- Na 2 (SO 4 )

Acid Structure Have a characteristic formula structure: “HX”  Where “H” is a hydrogen cation  Where “X” is an anion  So generally, if you see a formula for an ionic compound that starts with an “H” it is likely an acid Have a characteristic formula structure: “HX”  Where “H” is a hydrogen cation  Where “X” is an anion  So generally, if you see a formula for an ionic compound that starts with an “H” it is likely an acid

Naming Acids  Scenario 1 – The anion ends in the suffix “ide”  Add the prefix “hydro” to the anion  Change the suffix to “ic”  Add the word “acid” to the end  i.e. HF  hydrogen & fluoride   hydrofluoric acid  i.e. HCN  hydrogen & cyanide   hydrocyanic acid  Scenario 1 – The anion ends in the suffix “ide”  Add the prefix “hydro” to the anion  Change the suffix to “ic”  Add the word “acid” to the end  i.e. HF  hydrogen & fluoride   hydrofluoric acid  i.e. HCN  hydrogen & cyanide   hydrocyanic acid

Naming Acids  Scenario 2 – The anion ends with the suffix “ate”  Change the suffix of the anion to “ic”  Add the word “acid” to the end  Note: no need for the “hydro” prefix  Hint to remember – “If you ATE it, its Icky”  i.e. HNO 3  hydrogen & nitrate   nitric acid  i.e. H 2 SO 4  hydrogen & sulfate   Sulfuric acid  Scenario 2 – The anion ends with the suffix “ate”  Change the suffix of the anion to “ic”  Add the word “acid” to the end  Note: no need for the “hydro” prefix  Hint to remember – “If you ATE it, its Icky”  i.e. HNO 3  hydrogen & nitrate   nitric acid  i.e. H 2 SO 4  hydrogen & sulfate   Sulfuric acid

Naming Acids  Scenario 3 – The anion ends with the suffix “ite”  Change the suffix on the anion to “ous”  Add the word “acid” to the end  Note: no need for the “hydro” prefix  i.e. HNO 2  hydrogen & nitrite   nitrous acid  i.e. H 2 SO 3  hydrogen & sulfite   sulfurous acid  Scenario 3 – The anion ends with the suffix “ite”  Change the suffix on the anion to “ous”  Add the word “acid” to the end  Note: no need for the “hydro” prefix  i.e. HNO 2  hydrogen & nitrite   nitrous acid  i.e. H 2 SO 3  hydrogen & sulfite   sulfurous acid

Writing Acid Formulas  Use the prefix/suffix combinations to figure out the anion  Balance the charges with a H+ cation (s)  Write the formula  i.e. – permanganic acid   permanganate anion  MnO 4 -   HMnO 4  Use the prefix/suffix combinations to figure out the anion  Balance the charges with a H+ cation (s)  Write the formula  i.e. – permanganic acid   permanganate anion  MnO 4 -   HMnO 4

Naming Covalent Compounds  Prefixes are used to indicate the number of atoms  The prefix “mono” is only used for the second atom; no mono prefix needed for the first atom  The second atom named ends with the suffix, “ide”  Prefixes are used to indicate the number of atoms  The prefix “mono” is only used for the second atom; no mono prefix needed for the first atom  The second atom named ends with the suffix, “ide”  Prefixes:  1 – “mono”  2 – “di”  3 – “tri”  4 – “tetra”  5 – “penta”  6 – “hexa”  7 – “hept”  8 – “oct”  9 – “non”  10 - “deca”

Examples of Naming Covalent Compounds  N 2 H 4 :  Dinitrogen tetrahydride  SO 3 :  Sulfur trioxide  CO 2 :  Carbon dioxide  P 2 O 5 :  Diphosphorus pentoxide  PCl 3:  Phosphorus trichloride N2H4:N2H4:  Dinitrogen tetrahydride  SO 3 :  Sulfur trioxide  CO 2 :  Carbon dioxide P2O5:P2O5:  Diphosphorus pentoxide  PCl 3:  Phosphorus trichloride

Formulas for Covalent Compounds  Read the prefixes to determine the amount of each atom  Examples:  carbon tetrachloride:  CCl 4  dinitrogen trioxide:  N 2 O 3  carbon disulfide:  CS 2  dihydrogen monosulfide:  H 2 S  sulfur hexafluoride:  SF 6  Read the prefixes to determine the amount of each atom  Examples:  carbon tetrachloride:  CCl 4  dinitrogen trioxide: N2O3N2O3  carbon disulfide:  CS 2  dihydrogen monosulfide: H2SH2S  sulfur hexafluoride:  SF 6

Number of Atoms in a Formula  The number of atoms in a formula is determined by the subscripts  If there is no subscript, this means that there is only one of a particular atom i.e.: NaCl ○ 1 Na atom and 1 Cl atom ○ 2 atoms total  When you are dealing with polyatomic ions, remember that the subscript found outside of the brackets is applied to every atom inside the brackets by using the distributive property of multiplication i.e.: Mg(NO 3 ) 2 ○ 1 Mg atom, 2 N atoms, 6 O atoms ○ 9 atoms total  The number of atoms in a formula is determined by the subscripts  If there is no subscript, this means that there is only one of a particular atom i.e.: NaCl ○ 1 Na atom and 1 Cl atom ○ 2 atoms total  When you are dealing with polyatomic ions, remember that the subscript found outside of the brackets is applied to every atom inside the brackets by using the distributive property of multiplication i.e.: Mg(NO 3 ) 2 ○ 1 Mg atom, 2 N atoms, 6 O atoms ○ 9 atoms total

Molar Mass of Molecules & Compounds  To find the mass of a molecule/compound, simply add up all of the masses of the individual atoms in the compound  Value is known as the “Molar Mass” of a molecule/compound  i.e.: NaCl  i.e.: Mg(NO 3 ) 2  To find the mass of a molecule/compound, simply add up all of the masses of the individual atoms in the compound  Value is known as the “Molar Mass” of a molecule/compound  i.e.: NaCl  i.e.: Mg(NO 3 ) 2

Percent Composition by Mass  The percent composition by mass of a molecule/compound is simply the percentage of mass for each element in the molecule/compound  To calculate the percent composition:  Examples:  NaCl  Mg(NO 3 ) 2  The percent composition by mass of a molecule/compound is simply the percentage of mass for each element in the molecule/compound  To calculate the percent composition:  Examples:  NaCl  Mg(NO 3 ) 2