honors naming compounds notes
DESCRIPTION
Some science for evryoneTRANSCRIPT
Chemical Formulaindicates the relative number of atoms of each kind in a chemical compound.
Identify the number of atoms in each of the following compounds:
1. KCl= _____________________
2. C6H12O6=__________________
3. NH3=__________________
Finding the number of atoms in a compound with polyatomic ions
Compound What does it look like Numbers of expanded? atoms
1. MgCO3
2. Al(ClO4)3
Law of Definite Proportions
• Law stating that every pure substance always contains the same elements combined in the same proportions by weight.
• For example: H2O, will always have the same percent by weight, ex. 11.2% H and 88.8% O
Molecular FormulaRepresents the number and kind of atoms
in a molecule (not necessarily the smallest whole number ratio).
Structural Formulastructural formula indicates two-
dimensional arrangement of the bonds and lone pairs of electrons in a molecule.
Empirical Formula for Molecules (have covalent bonds)
• The chemical formula that represents the simplest (lowest) atomic ratio in which elements can combine.
• Formulas for molecular compounds are NOT NECESSARILY the empirical formula
Molecular Formula Empirical Formula
C2H6
C6H12O6
C4H8
C3H8
C6H10
C4H6
C2H4
C5H10
Empirical Formula for Ionic Compounds
ALWAYS WRITTEN IN EMPIRICAL FORM• The chemical formula that represents the simplest (lowest) atomic ratio
in which elements can combine.• Formulas for ionic compounds are the empirical formula because they are
ALWAYS written in the expressed as the lowest possible ratios.
Empirical Form
Ca2O2
Fe2O2
Pb2O4
Mg2O2
Empirical Formula for Ionic Compounds with Polyatomic Ions
Empirical Form
Fe2(CO3)2
Fe2(HSO4)2
Zn2(SO4)2
Pb2(SO3)2
Empirical or Molecular Formula
If written in molecular formula what is the empirical formula?
Type of Bond
C6H12O6
LiNO3
H2O2
C11H22O11
To determine how many atoms combine with one another in a compound we must
determine each elements OXIDATION NUMBER.
OXIDATION NUMBER
Predicting Ionic ChargesGroups 3 - 11: Many transition elements
have multiple oxidation states.Iron(II) = Iron(III) =
Predicting Ionic ChargesGroups 3 - 11: Some metals
have only one possible oxidation state.Zinc = Zn2+Silver = Ag+
Rules for assigning Oxidation Numbers
1. The atoms in a pure element have an oxidation number of zero.2. Alkali metals always have an oxidation number of +1; alkaline
earth metals always have an oxidation number of +2.3. Fluorine always has an oxidation number of -1.4. Oxygen has an oxidation number of -2 in almost all compounds.
Exceptions are in compounds with a halogen, when it has an oxidation number of +2, and in peroxides (H2O2), when it has an oxidation number of -1.
5. Hydrogen has an oxidation number of +1 in almost all compounds except when combined with a metal when it has an oxidation number of -1.
6. The sum of all the oxidation numbers in a neutral compound is zero.
7. The sum of all the oxidation numbers in a polyatomic ion is equal to the charge of the ion.
ASSIGNING OXIDATION NUMBERS
• A compound has a total charge of ZERO so set your equation equal to ZERO.
• Assign the variable X to your unknown oxidation number.
Given a compound, find the oxidation number of every element you know for certain. Then solve for others using algebra.
a. KMnO4
b. CaCO3
What is in common with the elements in the compound?
H2+1 O1
-2 Mg1+2F2
-1
Al2+3S3-2 Cu3
+1P1-3
Ca1+2Cl2-1 Fe2
+3O3-2
CRISS-CROSS METHOD to determine the chemical formula
1. Write the symbols for the elements side by side.2. Write the oxidation states of each element to the
top right of the symbol.When the nonmetal is combines with a metal, the oxidation state will always be the first number (the negative one) in the list of oxidation states.
3. Criss cross the charges DOWN and use the absolute values (-2 becomes 2).
4. Check to make sure the subscripts are the lowest ratio.
Write down the only cations on Table E: (positively charges ions)
Write down the only polyatomic ions that end in –ide.
Find the charge of the polyatomic ion using Table E
Put parenthesis around the polyatomic ion.
1. PO4
2. CO3
3. SO3
4. NH4
5. ClO
6. ClO2
7. HSO4
8. ClO4
9. CN
10. OH
11. S2O3
12. SCN
• If you see a group of atoms together with a charge it is a polyatomic ion from Table E.• Put the polyatomic ion within Parenthesis.• Find the charge of the polyatomic ion.• Use the criss-cross method to determine subscripts.
Na +1 CO3-2
How many atoms are present in the compound?
NH4+1 S-2
How many atoms are present in the compound?
Write the formula of the compound composed of the ions shown:a. Place all Polyatomic Ions in Parenthesis (Table E)b. Determine all oxidation numbers of elements and polyatomic ionsc. Use Criss-Cross Methodd. Reduce to Empirical Form if necessary
1. NH4 S
2. Na NO3
3. Cu Br
NAMING IONIC COMPOUNDS
• An Ionic compound can quickly be determined if a METAL is bonded to a NONMETAL.
• Naming Ionic compounds with metals that have only ONE oxidation state is fairly simple.
Of the following metals listed below, check off all the elements that have more than one oxidation state:
a. Mn___ b. Zn ___ c. K ____ d. Pb___
e. Mg___ f. Au ___ g. Ag ___ h. Ga ___
i. Sn __ j. Li ____ k. U ____ l. Cr ___
Naming Ionic Compounds that contain metals with only 1
oxidation state.
Binary Ionic CompoundsIonic compounds with only 2 different elements.
Name the metal and end the nonmetal in –ide.
For example: CaBr2 =
1. MgO= ________________________
2. CaCl2 = _______________________
3. AlBr3 = _______________________
4. Ag3N = _______________________
5. Al2O3 = ______________________
6. LiI = _________________________
7. BaF2 = _______________________
8. Zn2C = _______________________
9. Ba3N2 = ______________________
10. CdO = _Cadnium oxide__________Cadmium Oxide
11. Ga2S3 = _______________________
12. K3N = ________________________
13. SrO = ________________________
Ternary Ionic CompoundsIonic Compounds with 3
different elements.They usually contain Polyatomic
Ions (Table E)Name the following Polyatomic Ions:A. NO3
- _________ d. SO42- ___________
B. ClO2- _________ e. S2O3
2- __________
C. CO32- _________ f. SCN- ____________
Name the following Ternary compounds:
1. NaC2H3O2 _____________________
2. AgHCO3 _______________________
3. LiNO2 _________________________
4. Ga2(S2O3)3 ____________________
5. Ca3(PO4)2 _____________________
6. ZnSO3 __________________________
7. KClO3 ___________________________
8. Al(OH)3 _________________________
9. RbSCN __________________________
10. SrCO3 _________________________
Naming Ionic Compounds with Metals with Multiple oxidation
states (multiple charges): STOCK SYSTEM
1. Determine the oxidation state of the metal in the compound.
2. Name the metal, put the oxidation state in ROMAN NUMERALS in parenthesis and end the nonmetal in –ide.
Work Backwards and Start with the Empirical Formula to determine the Oxidation state of a Metal with
Multiple Oxidation StatesEmpirical Formula Write in the oxidation
number for the nonmetal or polyatomic ion you are sure of and criss-cross.
Non-reduced form with Oxidation States
Fe1O1 Fe O
Fe1(SO4)1 Fe (SO4)
Cu1(SO4)1 Cu (SO4)
Work Backwards and Start with the Empirical Formula to determine the Oxidation state of a Metal with
Multiple Oxidation States
Empirical Formula
Write in the oxidation number for the nonmetal or polyatomic ion you are sure of and criss-cross.
Non-reduced form with Oxidation States
Sn1(SO3)1 Sn (SO3)
Mn1(SO4)2 Mn (SO4)
Cr1(PO4)2 Cr (PO4)
Name the following compound using the Stock System:
1. Fe O ____________________________
2. Fe Cl2 ___________________________
3. Cu SO4 __________________________
4. Pb Cl2 ___________________________
5. Pb O2 ___________________________
6. Cu3(PO4)2 ________________________
7. Cu2 S ___________________________
8. Fe2(CrO4)3 ______________________
19. Sn CO3 _________________________
10. Sn F4 ___________________________
Name each of the following compounds, use Roman Numerals
only when necessary.Put a check next to every compound that begins
with a metal with more than 1 oxidation state.Put parenthesis around all the polyatomic ions.1. NH4 Cl _________________________
2. Pb SO4 _________________________
3. Co Cl3 __________________________
4. Ba (NO3)2 ______________________
5. Co2 (SO3)3 _____________________
6. KH ____________________________
7. NH4 F _________________________
8. K2Cr2O7 _______________________
9. Cu S __________________________
10. Cu ClO2 ______________________
11. Ag NO3 _______________________
12. Fe Cl3 ________________________
13. Cr F2 _________________________
14. Na Cl _________________________
15. Fe PO4 ______________________
16. Li F _________________________
17. Fe F3 _______________________
18. Al (OH)3 _____________________
19. Mg I2 ________________________
20. Fe Cl3 _______________________
Formula Writing for Ionic Compounds
1. All ionic compounds must be in empirical form. (Reduced Form)
2. If the compound ends in –ide, most likely it is a binary compound. Except for cyanide and hydroxide.
3. If the substance ends in –ate or –ite it contains a polyatomic ion. Put the polyatomic ion in parenthesis before you criss-cross.
4. Put the oxidation states on top and criss-cross the numbers.For example: Aluminum Sulfide =
Write the formulas for each of the following compounds:
Make sure you reduce it to empirical form.1. Aluminum Chloride ___________________
2. Silver Phosphate _____________________
3. Lithium Hydride ______________________
4. Magnesium Acetate __________________
5. Potassium Sulfite _____________________
6. Zinc Thiosulfate ____________________
7. Strontium Nitride ____________________
8. Calcium Oxide _______________________
9. Gallium Oxalate ______________________
10. Ammonium Hydroxide ________________
Writing formulas for compounds with metals with more than one oxidations state:
(Roman Numerals will be given)1. If there are Roman Numerals with the name, the Roman Numeral is
the charge of the metals.For example: Iron (II) Oxide= Fe+2O-2=Fe2O2=FeO
2. If the compound ends in –ate or –ite, most likely you should look on the polyatomic ion chart.
3. Write the metal, then look up the polyatomic ion and place it in parenthesis. Put the charges on top and criss-cross. Reduce if necessary.
For example: Zinc Carbonate=
Gold (III) Thiocyanate =
For each compound listed below, write the correct formula using the stock
system.1. Iron (II) Chloride _____________________
2. Lead (IV) Phosphide __________________
3. Tin (II) Oxide ________________________
4. Copper (I) Iodide _____________________
5. Nickel (III) Sulfide ____________________
6. Cobalt (II) Thiocyanate ______________
7. Manganese (IV) Oxide _________________
8. Titanium (IV) Chromate _________________
9. Iron (III) Sulfate _______________________
10. Lead (II) Nitrate ______________________
Naming Molecular Compounds
• What types of bonds are in molecular compounds? _____________________
• How can we tell if a formula has a covalent bond? ___________________________
Prefix System
Most nonmetals have more than 1 oxidation state, therefore you can use the Stock System (Roman Numerals) or the prefix system.
Molecular Prefix Number of Atoms12345678910
HOW TO NAME MOLECULAR COMPOUNDS
According to the number of atoms of each element, state the prefix for the number of each atom before the name of the element and end the nonmetal in –ide.
For example:P2O5 =CO2 =
The prefix mono only need to be used for the second half of the compound NOT the first element.
Name the following covalent compounds:
1. CI4 ________________________________
2. PCl5 ______________________________
3. SI6 _______________________________
4. P2S6 ______________________________
5. N3O4 ______________________________
6. SO2 ____________________________
7. N2O4 ___________________________
8. CO _____________________________
9. NF3 ____________________________
10. ICl5 ___________________________
11. H2S3 __________________________
12. N2O3 _________________________
13. ClF7 __________________________
14. SO3 ___________________________
15. NI5 ___________________________
16. BN2 __________________________
17. P2O5 _________________________
18. IF7 ___________________________
Naming Acids
1. Elements that begin with hydrogen are normally acids.
2. Naming Binary Acidsa. Begin with the word HYDRO- and end with
the non metal in –ICb. Then add the word ACID
For example: HCl= Hydrochloric acid
3. Naming Ternary Acidsa. Cover the hydrogen and look up the polyatomic ion being used.
b. If the polyatomic ion ends in –ITE change the ending to –OUS and add the word ACID.For example: HClO2 = chlorite = Chlorous Acid
c. If the polyatomic ion ends in –ATE change the ending to –IC and add the word acid.
For example: H2SO4 = sulfate = Sulfuric Acid
Name the following acids:
1. HCl _______________________________
2. HBr _______________________________
3. HF _______________________________
4. H2S ______________________________
5. H3P ______________________________
6. H2Se ___________________________
7. HI ______________________________
8. H2CO3 __________________________
9. H2C2O7 _________________________
10. HNO2 __________________________
11. H3PO4_________________________
12. H2SO3_________________________
13. H2S2O3________________________
For each of the following acids below, write the correct formula.
1. Sulfuric Acid ________________________
2. Hydrochloric Acid ____________________
3. Clorous Acid ________________________
4. Cloric Acid __________________________
5. Thiocyanic Acid _______________________
6. Acetic Acid _______________________
7. Nitric Acid ___________________________
8. Dichromic Acid _______________________
9. HydroIodic Acid ______________________
10. Nitrous Acid ________________________
How can you tell the difference between a binary acid and a ternary acid from its name?
Naming Ionic Compounds using the FormulaDetermining subscripts of elements or polyatomic in ionic compounds
Use Criss-cross method Example:
Naming ionic compounds with metals with only 1 oxidation state
Binary Ionic CompoundsIonic compounds with only 2 different elements.
Name the metal and end the nonmetal in –ide.
For example: CaBr2 = Calcium Bromide
Ternary Ionic CompoundsIonic Compounds with 3 different elements.•Name the metal and then name the polyatomic ion.
For example: KNO3 = Potassium Nitrate
Naming ionic compounds with metals with multiple oxidation state
1. Determine the oxidation state of the metal in the compound.
2. Name the metal, put the oxidation state in ROMAN NUMERALS in parenthesis and end the nonmetal in –ide.
Example: FeO= Iron (II) Oxide
Writing the Formula of Ionic Formulas using the name of the Ionic Compound
Formula Writing for Ionic Compounds
All ionic compounds must be in empirical form. (Reduced Form)If the compound ends in –ide, most likely it is a binary compound. Except for cyanide and hydroxide.If the substance ends in –ate or –ite it contains a polyatomic ion. Put the polyatomic ion in parenthesis before you criss-cross.Put the oxidation states on top and criss-cross the numbers.
For example:Zinc Carbonate= Zn+2(CO3) -2 =
Zn2(CO3)2 =Zn(CO3)
Gold (III) Thiocyanate = Au+3 (SCN) -1 = Au(SCN)3
Writing formulas for compounds with metals with more than one oxidations state:(Roman Numerals will be given)
If there are Roman Numerals with the name, the Roman Numeral is the charge of the metals.
2. If the compound ends in –ate or –ite, most likely you should look on the polyatomic ion chart.
3. Write the metal, then look up the polyatomic ion and place it in parenthesis. Put the charges on top and criss cross. Reduce if necessary.
For example: Iron (II) Oxide= Fe+2O-2=Fe2O2=FeO