Types of Compounds Chapter 5 Objectives 5.1 5.1 Apply ionic charge to writing formulas 5.1 Apply...
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Transcript of Types of Compounds Chapter 5 Objectives 5.1 5.1 Apply ionic charge to writing formulas 5.1 Apply...
Types of Compounds
Chapter 5
Objectives 5.1
• 5.1 Apply ionic charge to writing formulas
• 5.1 Apply formulas to name ionic compounds
• 5.1 Interpret the information in a chemical formula
Ionic “Bonds”
• Instead of Formula’s: Ratio’s
• Some atom’s want more electrons than the other wants to give up
• So they bind to two, or three
• Example: Li and O, Li wants to give up only 1 electron, but O wants 2 electrons
Practice Question
• What ratio of Mg and N are needed to make an Ionic compound that has a neutral charge?– Draw a Lewis electron dot diagram for N– Draw a Lewis electron dot diagram for Mg
• What ratio of Na and Br are needed to make an Ionic compound that has a neutral charge?
+1+2 General Ionic Charges -1-2-3
Ionic Nomenclature
• Only use Ionic Nomenclature when dealing with Ionic compounds– An ionic compound is formed when a metal
and a non metal come together and electrons are completely lost and gained
Fixed Oxidation State
• Some Metals will always lose the same amount of electrons. These metals have Fixed Oxidation States
• Alkali Metals = +1
• Alkaline Earth Metals = +2
• Aluminum = +3
Ionic Nomenclature
• Binary Compounds of Metals with Fixed Charges: Given Formula, Write the Name
• The order for names in a binary compound is first the cation, then the anion.
• Use the name of cation with a fixed oxidation state directly from the periodic table.
• The name of the anion will be made from the root of the element's name plus the suffix "-ide."
Practice Naming
• What is the name of the following?
• MgO
• Magnesium Oxide
• NaF
• Sodium Flouride
• CaS
• Calcium Sulfide
Ionic Nomenclature
• Given Name, Write Formula• The order in a formula is first the cation, then the
anion. • You must know the charges associated with
each cation and anion. • The sum of the positive charge and the sum of
the negative charges MUST add up to zero. • You MAY NOT adjust the charges of the cations
or anions to get a total charge of zero. • You MAY adjust the subscripts to get a total
charge of zero.
CATIONCATION + + ANIONANION ---> --->
COMPOUNDCOMPOUND
CATIONCATION + + ANIONANION ---> --->
COMPOUNDCOMPOUND
A neutral compound A neutral compound requiresrequires
equal number of + equal number of + and - charges.and - charges.
A neutral compound A neutral compound requiresrequires
equal number of + equal number of + and - charges.and - charges.
COMPOUNDS FORMED FROM IONS
COMPOUNDS FORMED FROM IONS
NaNa++ + Cl + Cl- - --> NaCl--> NaCl
Formulas of Ionic Compounds
Formulas of ionic compounds are determined from the charges on the ions
atoms ions
–
Na + F : Na+ : F : NaF
sodium + fluorine sodium fluoride formula
Charge balance: 1+ 1- = 0
Hint
• Cross the charges to find the amount you need.
• If it can be reduced, then do so– Ie if both are 2, then it is 1
Ionic Nomenclature
• What is the formula of the following?
• Potassium Oxide
• K2O
• Strontium Chloride• SrCl2
• Magnesium Nitride• Mg3N2
Ionic Nomenclature
• Potassium Phosphide• K3P
• Magnesium Sulfide• MgS• Radium Flouride• RaF2
Variable Charges
• The transition metals have variable charges, they are happy with losing a variety of electrons– This is because they can also lose some of
there D electrons and be stable
Transition Metals
Elements that can have more than one possible
charge MUST have a Roman Numeral to
indicate the charge on the individual ion.
1+ or 2+ 2+ or 3+
Cu+, Cu2+ Fe2+, Fe3+
copper(I) ion iron(II) ion
copper (II) ion iron(III) ion
Variable Charges
• Formula to Name• 1) Find the charge of the cation by
– Finding total charge of anion and dividing by number of cations
• Example: FeCl3– We have 3 Chlorines, each has a -1 charge– The Fe needs to be +3 to balance it out
• 2) Say the cation with its Roman Numeral– Iron (III) Chloride
Variable Charges
• What is the name?• AuF3
• Gold (III) Flouride• AgF• Silver (I) Flouride• PbO2
• Lead (IV) Oxide
Variable Charges
• SnF2
• Tin (II) Flouride• MnO2
• Manganese (IV) Oxide• CrN• Chromium (III) Nitride• Sn3N4
• Tin (IV) Nitride
Variable Charges
• Name to Formula
• The Roman Numeral tells you the charge
• Balance the formula
• Iron (III) Oxide– Fe has a +3 charge as denoted by the III– Oxygen always has a -2 charge– Cross them (Balance)– Fe2O3
Variable Charge
• What’s the formula?
• Lead (IV) Sulfide• PbS2
• Copper (I) Chloride
• CuCl
• Silver (I) Nitride
• Ag3N
Variable Charge
• Gold (III) Arsenide
• AuAs
• Tin (II) Bromide• SnBr2
• Cobalt (III) Oxide• Co2O3
Writing a Formula
Write the formula for the ionic compound that will form between Ba2+ and Cl.
Solution:
1. Balance charge with + and – ions
2. Write the positive ion of metal first, and the
negative ion Ba2+ Cl
Cl3. Write the number of ions needed as
subscripts BaCl2
Learning Check
Write the correct formula for the compounds containing the following ions:
1. Na+, S2-
a) NaS b) Na2S c) NaS2
2. Al3+, Cl-
a) AlCl3 b) AlCl c) Al3Cl
3. Mg2+, N3-
a) MgN b) Mg2N3 c) Mg3N2
Solution
1. Na+, S2-
b) Na2S
2. Al3+, Cl-
a) AlCl3
3. Mg2+, N3-
c) Mg3N2
Naming CompoundsNaming Compounds
• 1. Cation first, then anion
• 2. Monatomic cation = name of the element
• Ca2+ = calcium ion
• 3. Monatomic anion = root + -ide
• Cl = chloride
• CaCl2 = calcium chloride
Binary Ionic Compounds:Binary Ionic Compounds:
Naming Binary Ionic Compounds
Examples:
NaCl
ZnI2
Al2O3
sodium chloride
zinc iodide
aluminum oxide
Learning Check
Complete the names of the following binary compounds:
Na3N sodium ________________
KBr potassium ________________
Al2O3 aluminum ________________
MgS _________________________
Mixed Review
• Given the name, write the formula
• Given the formula, write the name
• 1) Sodium Oxide
• 2) Lead (II) Nitride
• 3) Cesium Iodide
• 4) RbF
• 5) AuO
Mixed Review
• 6) SrCl2
• 7) CoS
• 8) Ag2Se
• 9) Manganese (IV) Chloride
• 10) Radium Nitride
Answers to Review
• 1) Na2O• 2) Pb3N2
• 3) CsI
• 4) Rubidium Flouride
• 5) Gold (II) Oxide
Answers to Review
• 6) Strontium Chloride
• 7) Cobalt (II) Sulfide
• 8) Silver (I) Selenide• 9) MnCl4• 10) Ra3N2
Objectives 5.2
• 5.2 Apply organic nomenclature to name hydrocarbons
• 5.2 Distinguish among allotropes of an element.
• 5.2 Apply formulas to name molecular compounds
Naming Molecular Compounds
CH4 methaneBCl3 boron trichloride
CO2 Carbon dioxide
All are formed from two or more nonmetals.
Ionic compounds generally involve a metal and nonmetal (NaCl)
Molecular (Covalent) Nomenclaturefor two nonmetals
• Prefix System (binary compounds)
1. Less electronegative atom comes first.
2. Add prefixes to indicate # of atoms. Omit mono- prefix on the FIRST element. Mono- is OPTIONAL on the SECOND element (in this class, it’s NOT optional!).
3. Change the ending of the second element to -ide.
PREFIXmono-di-tri-tetra-penta-hexa-hepta-octa-nona-deca-
NUMBER123456789
10
Molecular Nomenclature Prefixes
• CCl4
• N2O
• SF6
• carbon tetrachloride
• dinitrogen monoxide
• sulfur hexafluoride
Molecular Nomenclature: Examples
• arsenic trichloride
• dinitrogen pentoxide
• tetraphosphorus decoxide
• AsCl3
• N2O5
• P4O10
More Molecular Examples
Learning Check
Fill in the blanks to complete the following names of covalent compounds.
CO carbon ______oxide
CO2 carbon _______________
PCl3 phosphorus _______chloride
CCl4 carbon ________chloride
N2O _____nitrogen _____oxide
Learning Check
1. P2O5 a) phosphorus oxide
b) phosphorus pentoxide
c) diphosphorus pentoxide
2. Cl2O7 a) dichlorine heptoxide
b) dichlorine oxide
c) chlorine heptoxide
3. Cl2 a) chlorine
b) dichlorine
c) dichloride
A flow chart for naming binary compounds.
Mixed Practice
1. Dinitrogen monoxide
2. Potassium sulfide
3. Copper (II) nitrate
4. Dichlorine heptoxide
5. Chromium (III) sulfate
6. Iron (III) sulfite
7. Calcium oxide
8. Barium carbonate
9. Iodine monochloride
Mixed Practice
1.1. BaIBaI22
2.2. PP44SS33
3.3. Ca(OH)Ca(OH)22
4.4. FeCOFeCO33
5.5. NaNa22CrCr22OO77
6.6. II22OO55
7.7. Cu(ClOCu(ClO44))22
8.8. CSCS22
9.9. BB22ClCl44
NONO33--
nitrate ionnitrate ion
NONO22--
nitrite ionnitrite ion
Polyatomic Ions
Polyatomic Ions
You can make additional polyatomic You can make additional polyatomic ions by adding a Hions by adding a H++ to the ion! to the ion!
COCO33 -2-2 is carbonate is carbonate
HCOHCO33–– is hydrogen carbonate is hydrogen carbonate
HH22POPO44–– is dihydrogen phosphate is dihydrogen phosphate
HSOHSO44–– is hydrogen sulfate is hydrogen sulfate
Polyatomic IonsPolyatomic Ions
Ternary Ionic Nomenclature
Writing Formulas
• Write each ion, cation first. Don’t show charges in the final formula.
• Overall charge must equal zero.– If charges cancel, just write symbols.– If not, use subscripts to balance charges.
• Use parentheses to show more than one of a particular polyatomic ion.
• Use Roman numerals indicate the ion’s charge when needed (stock system)
Monatomic Ions
Examples of Older Names of Cations formed from Transition Metals
(you do not have to memorize these)
Diatomic Elements
• Dr. HOFBrINCl
• These elements are found naturally as two elements and do NOT use a prefix
• O2 is Oxygen, not DiOxygen
Allotropes
• Molecules of a single element that different in molecular structure or crystalline structure– Oxygen and Ozone– Diamond, Graphite, Charcoal, Fullerenes,
Acetylenic
Hydrocarbons
• Composed of Carbon Chain and hydrogens (functional groups discussed later)
• Methane Hexane
• Ethane Heptane
• Propane Octane
• Butane Nonane
• Pentane Decane