Presentation on theme: "Chapter 9 Naming Compounds and Writing Formulas Ionic Compounds; Molecular Compounds and Acids."— Presentation transcript:
Chapter 9 Naming Compounds and Writing Formulas Ionic Compounds; Molecular Compounds and Acids
Types of Compounds Compound- Formed when atoms of two or more elements combine CHEMICALLY. Law of Definite Proportions- In ANY CHEMICAL compound the elements always combine in the same proportion by mass. This agrees with Dalton’s Atomic Theory that atoms combine in small whole # ratios.
Molecular Compounds Two Types of Compounds- 1. Molecular Compounds 2. Ionic Compounds 1. Molecular Compounds Formed between 2 or more NONMETALS (Covalent Bond- Share Electrons) - Liquid or gas at room temp. and have relatively low melting and boiling points.
Molecule Molecule- NEUTRAL no charge, group of atoms that act like a unit (one thing) Molecules of a compound are all identical to each other Molecules of different compounds are different. Ex: CO 2 (1C : 2 O); CO (1C : 1O)
Molecular Formula Tells the number and kinds of atoms in a molecule of a compound. (CO 2 & CO) Nonmetal + Nonmetal Covalent Bond: Share Electrons Diatomic molecules: 7 nonmetallic elements that are always paired and exist a molecules NOT atoms. MEMORIZE: H O N Cl Br I F Hydrogen H 2 ; Oxygen O 2 ; Nitrogen N 2 ; Hydrogen H 2 ; Oxygen O 2 ; Nitrogen N 2 ; Chlorine Cl 2 ; Bromine Br 2 ; Iodine I 2 ; Fluorine F 2
Ionic Compounds -M-M-M-Metal + Nonmetal -M-M-M-Made up of IONS -R-R-R-Relatively high melting and boiling points -N-N-N-NEUTRAL (ion charges cancel out; total + charge = total – charge)
ION Atom or group of atoms that have an UNEQUAL number of protons and electrons (#p+ does NOT = #e-) have a + or – charge Cations- atom or group of atoms with + charge Metals Lose electrons When naming cations the name stays the same as the element. EX: Na + = sodium ion; Al +3 = aluminum ion
Cation Charges ionic charges of Group A metals (see front of periodic chart) ionic charges of Group B metals (transitional metals) – see back of periodic chart Roman Numerals – are used to indicate the charge of a transitional metal. Examples: Copper I = Cu + ; Copper II = Cu +2 Lead II = Pb +2 ; Lead IV = Pb +4 Lead II = Pb +2 ; Lead IV = Pb +4
Anions Atom or group of atoms with a – charge Nonmetals Gain electrons When naming anions the ending changes to “ide” Ex: chlorine becomes chloride (Cl - ); oxygen becomes oxide(O -2 ); nitrogen becomes nitride (N -3 )
Polyatomic Ions Tightly bound group of atoms that act as a unit (one thing) and carry a charge. Also called Radicals Most end in “ite” or “ate”; “ite” ending has one less oxygen than “ate” ending. Examples; chlorite ClO 2 -1 ; chlorate ClO 3 -3 Except: hydorxide (OH - ); cyanide (CN - ); ammonium (NH 4 + ). Hypo – means 1 less oxygen (hypodermic means under the skin) hypochlorite ClO - Per – means 1 more oxygen perchlorate ClO 4 -
Formula Unit (FU) Lowest whole number ration on IONS in an ionic compound. - Ionic Compounds are NOT MOLECULES they are called Formula Units. - Ionic Compounds are NOT MOLECULES they are called Formula Units. Chemical Formula shows the kinds and number of atoms in the SMALLEST UNIT of a compound. The most positive element (metallic) is written first. EX: H 2 O = 2 Hydrogen atoms + 1 Oxygen atoms CO 2 = 1 Carbon atom + 2 Oxygen atoms
Homework Questions What are the differences between an ionic compound and molecular compound? (3) Answer: Ionic- made up of ions; metal + nonmetal; High BP & MP; Formula Unit Molecular- made up of nonmetals; share electrons covalent bonds; usually liquids or gases at room temp.; Molecules
Homework Questions Why aren’t ionic compounds molecules? Ionic Compounds are Formula Units (FU’s) and molecules are made up of 2 or more nonmetals What is the smallest ratio of an ionic compound called? Formula Unit (FU)
Name the 7 diatomic elements and write their formulas correctly. Hydrogen; H2 Oxygen; O2 Nitrogen; N2 Chlorine; Cl2 Bromine; Br2 Iodine; I2 Fluorine; F2
Homework Questions cont. Metals form + ions called ___________. Nonmetals form - ions called _______. What group of metals have more than one possible charge? Group B metals; transitional metals What is a polyatomic ion? A group of atoms that act as a single unit and carry a charge.
Naming compounds and Writing Formulas Binary compound- Simplest compound made up of 2 elements Examples: [ – NaCl ] [iron II chloride – ] [iron II chloride – ] (NAMING) 1.) element with the positive ionic charge is written first. ( ) Group A Metals – metal name is written. Example Na+ = sodium Group B Metals ( ) – Examples : Fe +2 = Iron II Examples : Fe +2 = Iron II Hg + = ____________ Hg + = ____________ Sn +4 = ____________ Sn +4 = ____________ ** Use the back of your periodic chart (Common Metal Ions with more than 1 ionic charge!) Sodium chloride FeCl 2 metals Transitional Roman Numeral Indicates the charge. Mercury I Tin IV
2.) element with the negative ionic charge is written next. ( ) 2.) element with the negative ionic charge is written next. ( ) Change the ending of the nonmetal to ( ) Nonmetal marries the metal and changes its name to “ide” like a bride. Examples: chlorine – chloride Bromine - ________________ Bromine - ________________ Oxygen - ________________ Oxygen - ________________ nonmetal ide bromide oxide
USE THE RULES ABOVE TO NAME THE BINARY IONIC COMPONDS BELOW: 1. MgO______________5.) FeCl 3 ____________ 2. BaS ______________6.) SnBr 4 ____________ 3. Na 3 N _____________7.) K 3 P ____________ 4. Cu 2 O _____________8.) PbS ____________ Magnesium oxideIron III chloride Barium SulfideTin IV bromide Sodium nitridePotassium phosphide Copper I oxideLead II sulfide
WRITING FORMULAS 1.) write the ion for the metal first Group A Metals –Examples: Lithium – Li + Aluminum - ___ Magnesium - ___ Rubidium - ___ Aluminum - ___ Magnesium - ___ Rubidium - ___ Group B Metals – Examples: Tin II – Sn +2 Copper I - ____ Mercury II - ____ Lead IV - ____ Copper I - ____ Mercury II - ____ Lead IV - ____ Al +3 Mg +2 Rb +1 The Roman Numeral indicates the charge Cu +1 Hg +2 Pb +4
write the ion for the non-metal Group VA, VIA, VIIA The number of the charge = Examples: sulfide = 8 – 6 = 2 ion = phosphide = ______ phosphide = ______ Iodide = _____ Iodide = _____ 8 – the groupA number S -2 P -3 I-I-
Cross-Over-Method Place the charge number of the metal as the subscript to the nonmetal and the charge number of the nonmetal as the subscript to the metal. You must reduce the charges if you can. Examples: Lithium Fluoride Magnesium Fluoride Potassium SulfideCopper I Chloride Aluminum Nitride Chromium III Sulfide Li + F - = LiFMg +2 F - =MgF 2 K + S -2 = K 2 SCu + Cl - = CuCl Al +3 N -3 = AlNCr +3 S -2 = Cr 2 S 3
USE THE RULES ABOVE TO WRITE FORMULAS FOR THE BINARY IONIC COMPOUNDS: Calcium Fluoride __________ Rubidium Iodide ___________ Sodium Phosphide ________Strontium chloride__________ Mercury I Oxide ___________Tin II Sulfide______________ Iron III nitride _____________ Copper I Selenide___________ Ca +2 F - =Rb + I - = Sr +2 Cl - = Hg + O -2 =Sn +2 S -2 = Fe +3 N -3 = Cu + Se -2 = CaF 2 RbI Na 3 PSrCl 2 Hg 2 O SnS FeNCu 2 Se Na + P 3 Classwork and homework worksheet 2 & 3 Binary Ionic Compounds.
Ternary Compounds Ternary Compounds are _________ and contain a _____________________. POLYATOMIC ION – A group of atoms that act as a single unit and carry a charge. A group of atoms that act as a single unit and carry a charge. Polyatomic ions end in “ “ or “ “ EXCEPTIONS: (OH) - (CN) - (CN) - *only (+) poly atomic ions (NH 4 ) + (PH 4 ) + Polyatomic Ion Ionic hydroxide iteate cyanide ammonium phosphonium
(Naming) Rules are similar to Binary ionic compounds. Element with positive ionic charge is written first. ( ) Group A Metals: name simply written Ex. Ca 2+ - Group A Metals: name simply written Ex. Ca 2+ - Group B Metals: need a roman numeral Ex. Pb 2+ _________ Group B Metals: need a roman numeral Ex. Pb 2+ _________ cation calcuim Lead II
2. Polyatomic ion ( ) written next. 2. Polyatomic ion ( ) written next. Write the name as it appears on the back of the Periodic Chart. Write the name as it appears on the back of the Periodic Chart. Ex. (C 2 H 3 O 2 ) - Ex. (C 2 H 3 O 2 ) - (Cr 2 O 7 ) 2- (Cr 2 O 7 ) 2- Naming Examples: LiCO 3 Be(CN) 2 Be(CN) 2 Sn(SO 4 ) 2 Sn(SO 4 ) 2 radical acetate dichromate Lithium carbonate Beryllium cyanide Tin IV sulfate
USE THE RULES ABOVE TO NAME THE TERNARY IONIC COMPOUNDS BELOW: MgSO 4 ___________________________ NaNO 3_ ___________________________ CaCO 3 ___________________________ NaOH __________________________ NaOH __________________________ Ba(ClO 2 ) 2 ________________________ Ba(ClO 2 ) 2 ________________________ Magnesium sulfate Sodium nitrate Calcium carbonate Sodium hydroxide Barium chlorite
Ternary Naming Continued Fe 2 (C 4 H 4 O 6 ) 3 __________________ (NH 4 ) 3 PO 4 ________________________ Cu 2 CrO 4 __________________________ Hg(NO 2 ) __________________________ Al 2 (SO 4 ) 3 __________________________ Iron III tartrate Ammonium phosphate Copper I chromate Mercury I nitrite aluminum sulfate
Writing Ternary Ionic Formulas Write the ion for the metal first. –Group A Metals – Ex. Calcium Rubidium Rubidium Boron Boron Group B Metals – The Roman Numeral tells you the charge number. Ex. Iron IIILead IV Mercury ITin II Mercury ITin II Group # = charge Group 2 = Ca +2 Group 1 = Rb +1 Group 3 = B +3 Fe +3 Pb+4 Hg +1Sn +2
Write the polyatomic ion next (USE PARENTHESIS) *Remember polyatomic ions end in “ “ or “ “ “ “ or “ “ except (OH) - and (CN) - except (OH) - and (CN) -Examples:SulfiteCarbonatePhosphateNitrite iteate hydroxide cyanide SO 3 -2 CO 3 -2 PO 4 -3 NO 2 -
Cross-Over-Method write the charge number of the metal as the subscript of the polyatomic ion. (You MUST use PARENTHESIS if the subscript is 2 or greater but DO NOT use Parenthesis if the subscript is 1) 2. write the charge number of the polyatomic ion as the subscript of the metal. *You must reduce if you can but NEVER change the polyatomic ion!! DO NOT TOUCH THE POLYATOMIC ION !! DO NOT CHANGE THE FORMULA OF THE POLYATOMIC ION !! DO NOT CHANGE THE FORMULA OF THE POLYATOMIC ION !! Examples: Magnesium nitrate Aluminum sulfate Aluminum sulfate Iron II sulfite Iron II sulfite Iron III sulfite Iron III sulfite Tin IV nitrate Tin IV nitrate
DO NOT TOUCH THE POLYATOMIC ION DO NOT TOUCH THE POLYATOMIC ION DO NOT CHANGE THE FORMULA OF THE POLYATOMIC ION !! DO NOT CHANGE THE FORMULA OF THE POLYATOMIC ION !!Examples: Magnesium nitrate Aluminum sulfate Aluminum sulfate Iron II sulfite Iron II sulfite Iron III sulfite Iron III sulfite Tin IV nitrate Mg +2 NO 3 - = Mg(NO 3 ) 2 Al +3 SO 4 -2 = Al 2 (SO 4 ) 3 Fe +2 SO 3 -2 = FeSO 3 Fe +3 SO 3 -2 = Fe 2 (SO 3 ) 3 Sn +4 NO 3 - = Sn(NO 3 ) 4
USE THE RULES ABOVE TO WRITE TERNARY FORMULAS FOR THE COMPOUNDS Ammonium sulfide __________________ Silver chromate ____________________ Iron III tartrate _____________________ Beryllium hydroxide ________________ aluminum oxalate _________________ Copper I cyanide ___________________ Nickel carbonate ___________________ +1;-2 (NH 4 ) 2 S +1;-2 Ag 2 CrO 4 +3;-2 Fe 2 (C 4 H 4 O 6 ) 3 +2;-1 Be(OH) 2 +3;-2 Al 2 (C 2 O 4 ) 3 +1;-1 CuCN +2;-2 NiCO 3
Molecular Compounds Writing names and Formulas
Molecular Compounds Made up of 2 or more NONMETALS (NO METALS or IONS) Share electrons when bonding Sharing Electrons is called COVALENT BONDING The smallest unit of a molecular compound is called a MOLECULE.
(NAMING) To write the name, write 2 words 1.) the non-metal closest to the metals on the periodic chart is written first. 2.) Prefixes are used to tell how many atoms of each element are in the compound. –1 6 –2 7 –3 8 –49–49–49–49 –5 10 heptadi hexa mono tri tetra penta octa nona deca
Exception: don’t write mono- if there is only one of the first element. 3.) The second element always uses a prefix and ends in “ _ide ”. 4.)No double vowels when writing names (oa, oo) Ex. CO carbon monoxide CO 2 carbon dioxide P 2 O 5 diphosphorus pentoxide
Name These N2ON2ON2ON2O Dinitrogen monoxide NO 2 Nitrogen dioxide Cl 2 O 7 Dichlorine heptoxide CBr 4 Carbon tetrabromide SiO 2 silicon dioxide silicon dioxide P2O3P2O3P2O3P2O3 Diphosphorus trioxide
(FORMULA WRITING) NO CRISS CROSSING Nitrogen trioxide _________carbon tetrafluoride _______ Diiodine decachloride _____ phosphorous triiodide ______ Sulfur hexabromide _______nitrogen pentafluoride ______ Diphosphorous trisulfide ____carbon tetrabromide ______ NO 3 CF 4 I 2 Cl 10 PI 3 SBr 6 NF 5 P2S3P2S3 CBr 4 Examples: Phosphorous pentachloride - PCl 5 Dinitrogen trisulfide – N 2 S 3
Acids Writing names and Formulas
Acids Compounds that give off hydrogen ions when dissolved in water. Must have H in them. will always be some H next to an anion. The anion determines the name.
Naming acids If the anion attached to hydrogen is ends in -ide, put the prefix hydro- and change - ide to -ic acid HCl - hydrogen ion and chloride ion hydrochloric acid H 2 S hydrogen ion and sulfide ion hydrosulfuric acid
Naming Acids If the anion has oxygen in it it ends in -ate or -ite change the suffix -ate to -ic acid HNO 3 Hydrogen and nitrate ions Nitric acid change the suffix -ite to -ous acid HNO 2 Hydrogen and nitrite ions Nitrous acid
Name these HF H3PH3PH3PH3P H 2 SO 4 H 2 SO 3 HCN H 2 CrO 4 Hydrofluoric acid Hydrophosphoric acid sulfuric acid sulfurous acid hydrocyanic acid chromic acid
Writing Acid Formulas/Naming Hydrogen will always be first name will tell you the anion make the charges cancel out Starts with hydro- if no oxygen in the acid, -ide ending becomes –ic Ex. HCl = hydochloric acid no hydro, -ate ending from polyatomic ion becomes -ic, H 2 SO 4 = sulfuric acid -ite ending becomes –ous, H 2 SO 3 = sulfurous acid -ite ending becomes –ous, H 2 SO 3 = sulfurous acid
Write formulas for these hydroiodic acid acetic acid carbonic acid phosphorous acid hydrobromic acid HI HC 2 H 3 O 2 H 2 CO 3 H 3 PO 3 HBr