Naming Binary Molecular Compounds and Ionic Compounds Binary

Naming Binary Molecular Compounds and Ionic Compounds

Binary Molecular Compounds § Compounds between two nonmetals § First element in the formula is named first. § Keeps its element name § Gets a prefix if there is a subscript on it § Second element is named second § Use the root of the element name plus the -ide suffix § Always use a prefix on the second element

§ 1 = mon(o) § 2 = di § 3 = tri § 4 = tetra § 5 = penta § 6 = hexa § 7 = hepta § 8 = octa § 9 = nona § 10 = deka List of Prefixes

Naming Binary Compounds P 2 O 5 = diphosphorus pentoxide CO 2 = carbon dioxide CO = carbon monoxide N 2 O = dinitrogen monoxide

Practice – Write the Formula Compound Name Compound Formula Carbon dioxide Carbon monoxide Diphosphorus pentoxide Dinitrogen monoxide Silicon dioxide Carbon tetrabromide Sulfur dioxide Phosphorus pentabromide Iodine trichloride Nitrogen triiodide Dinitrogen trioxide Check next slide for answers

Answers – Write the Formula Compound Name Compound Formula Carbon dioxide CO 2 Carbon monoxide CO Diphosphorus pentoxide P 2 O 5 Dinitrogen monoxide N 2 O Silicon dioxide Si. O 2 Carbon tetrabromide CBr 4 Sulfur dioxide SO 2 Phosphorus pentabromide PBr 5 Iodine trichloride ICl 3 Nitrogen triiodide NI 3 Dinitrogen trioxide N 2 O 3

Practice – Name the Compounds Compound Formula Compound Name N 2 O 4 SO 3 NO NO 2 As 2 O 5 PCl 3 CCl 4 H 2 O Se. F 6 Check next slide for answers

Answers – Name the Compounds Compound Formula Compound Name N 2 O 4 dinitrogen tetroxide SO 3 sulfur trioxide NO nitrogen monoxide NO 2 nitrogen dioxide As 2 O 5 diarsenic pentoxide PCl 3 phosphorus trichloride CCl 4 carbon tetrachloride H 2 O dinitrogen monoxide Se. F 6 selenium hexafluoride

Ions ØCation: A positive ion ØMg 2+, NH 4+ ØAnion: A negative ion ØCl-, SO 42 -

Predicting Ionic Charges Group 1: Lose 1 electron to form 1+ ions H+ Li+ Na+ K+

Predicting Ionic Charges Group 2: Loses 2 electrons to form 2+ ions Be 2+ Mg 2+ Ca 2+ Sr 2+ Ba 2+

Predicting Ionic Charges B 3+ Al 3+ Ga 3+ Group 13: Loses 3 electrons to form 3+ ions

Predicting Ionic Charges Neither! Group 13 elements rarely form ions. Group 14: Lose 4 electrons or gain 4 electrons?

Predicting Ionic Charges N 3 - Nitride P 3 - Phosphide As 3 - Arsenide Group 15: Gains 3 electrons to form 3 - ions

Predicting Ionic Charges O 2 - Oxide S 2 - Sulfide Se 2 - Selenide Group 16: Gains 2 electrons to form 2 - ions

Predicting Ionic Charges F 1 - Fluoride Cl 1 - Chloride Br 1 - Bromide I 1 - Iodide Group 17: Gains 1 electron to form 1 - ions

Predicting Ionic Charges Group 18: Stable Noble gases do not form ions!

Predicting Ionic Charges Groups 3 - 12: Many transition elements have more than one possible oxidation state. Iron(II) = Fe 2+ Iron(III) = Fe 3+

Predicting Ionic Charges Groups 3 - 12: Some transition elements have only one possible oxidation state. Zinc = Zn 2+ Silver = Ag+

Writing Ionic Compound Formulas Example: Barium nitrate 1. Write the formulas for the cation and anion, including CHARGES! 2. Check to see if charges are balanced. 3. Balance charges , if necessary, using subscripts. Use parentheses if you need more than one of a polyatomic ion. Ba 2+ ( NO 3 -) 2 Not balanced!

Writing Ionic Compound Formulas Example: Ammonium sulfate 1. Write the formulas for the cation and anion, including CHARGES! 2. Check to see if charges are balanced. 3. Balance charges , if necessary, using subscripts. Use parentheses if you need more than one of a polyatomic ion. + ( NH 4 ) SO 422 2 Not balanced!

Writing Ionic Compound Formulas Example: Iron(III) chloride 1. Write the formulas for the cation and anion, including CHARGES! 2. Check to see if charges are balanced. 3. Balance charges , if necessary, using subscripts. Use parentheses if you need more than one of a polyatomic ion. Fe 3+ Cl 3 3 Not balanced!

Writing Ionic Compound Formulas Example: Aluminum sulfide 1. Write the formulas for the cation and anion, including CHARGES! 2. Check to see if charges are balanced. 3. Balance charges , if necessary, using subscripts. Use parentheses if you need more than one of a polyatomic ion. 3+ Al 2 2 S 3 Not balanced!

Writing Ionic Compound Formulas Example: Magnesium carbonate 1. Write the formulas for the cation and anion, including CHARGES! 2. Check to see if charges are balanced. 2+ Mg CO 32 - They are balanced!

Writing Ionic Compound Formulas Example: Zinc hydroxide 1. Write the formulas for the cation and anion, including CHARGES! 2. Check to see if charges are balanced. 3. Balance charges , if necessary, using subscripts. Use parentheses if you need more than one of a polyatomic ion. Zn 2+ ( OH- ) 2 Not balanced!

Writing Ionic Compound Formulas Example: Aluminum phosphate 1. Write the formulas for the cation and anion, including CHARGES! 2. Check to see if charges are balanced. 3+ Al 3 PO 4 They ARE balanced!

Naming Ionic Compounds Ø Cation first, then anion Ø Monatomic cation = name of the element Ø Ca 2+ = calcium ion Ø Monatomic anion = root + -ide Ø Cl- = chloride Ø Ca. Cl 2 = calcium chloride

Naming Ionic Compounds (continued) Metals with multiple oxidation states Ø some metal forms more than one cation Ø use Roman numeral in name Ø Pb. Cl 2 Ø Pb 2+ is cation Ø Pb. Cl 2 = lead(II) chloride