section 2.8 naming simple compounds return to toc 10/14/2015 chemistry 1 vocabulary - review q: what...
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Section 2.8
Naming Simple Compounds
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04/22/23Chemistry
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Vocabulary - ReviewVocabulary - ReviewQ: What is a cation?A: A positive ion formed by a metal
Examples: Na+ Ca 2+ Al 3+
Q: What is an anion?A: A negative ion formed by a nonmetal.
Examples: H- F- O 2- P 3-
Q: What is a polyatomic ion?A: A group of charged atoms NH4
+ SO42-
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Section 2.8
Naming Simple Compounds
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Ionic CompoundsAttraction between + ions and - ions
Electrons go from metals to nonmetals
electron transfer
metal nonmetal ion+ ion–
Electrons lost = Electrons gain
NOTE: the net charge on the compound is zero
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Section 2.8
Naming Simple Compounds
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Formation of Ionic Compounds
Section 2.8
Naming Simple Compounds
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Ionic Bonding
What happens when an atom of sodium reacts with an atom of chlorine?
Na Na+ + 1e-
Cl + 1e- Cl-
Na + Cl + 1e- Na+Cl- + 1e-
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Naming Simple Compounds
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Ionic Bonding
We write Na+Cl- as simply NaCl
• The ionic compound is neutral – this means the net (overall) charge is = 0.
• Now let’s try for cesium reacting with sulfur.
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Naming Simple Compounds
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Ionic Bonding
Cs Cs+ + 1e-
S + 2e- S2-
Cs + S + 2e- Cs+S2- + 1e-
This equation is not balanced. What must be done to correct this?
Solution:
1. Write the symbol for each ion present
2.Make sure you include the charge of each ion 6
Section 2.8
Naming Simple Compounds
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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
3. Write the number of ions needed as
subscripts BaCl2 (NOTE WE CRISSCROSSED THE CHARGES)
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Ionic Compounds--Example: Sodium and oxygen react
1. You have to balance the charges. 2. You do this by criss-crossing the value of the charge
(not the + or -)
Sodium oxideNa+ O2-
Na2O we do not write the 1 as a subscript
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Ionic Compounds
Lithium iodide
Li+ I –
LiI
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Ionic Compounds
Magnesium oxide
Mg2+ O2-
Mg2O2 MUST be reduced to MgO
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Section 2.8
Naming Simple Compounds
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Ionic Compounds
Let’s try a few:
Barium nitride
Ba3N2
Aluminum oxide
Al2O3
Cesium iodideCsI
Sodium fluorideNaF
Strontium bromide
SrBr2
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Section 2.8
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Learning Check
Write the correct formula for the compounds containing the following ions:
A. Na+, S2-
B. Al3+, Cl-
C. Mg2+, N3-
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Solution
A. Na+, S2-
Na2S
B. Al3+, Cl-
AlCl3
C. Mg2+, N3-
Mg3N2
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• Binary Compounds Composed of two elements Ionic and covalent compounds included
• Binary Ionic Compounds Metal—nonmetal
• Binary Covalent Compounds Nonmetal—nonmetal
Naming Compounds
Section 2.8
Naming Simple Compounds
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• Binary Compounds Composed of two elements
• Binary Ionic Compounds Metal—nonmetal
• Binary Covalent Compounds Nonmetal—nonmetal
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• Binary ionic compounds contain positive cations and negative anions. Type I compounds
• Metal present forms only one cation.
Type II compounds • Metal present can
form 2 or more cations with different charges.
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Naming Simple Compounds
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1. Contain 2 different elements
2. The cation is always named first and the anion second.
2. A cation has same name as element.Examples: Ca2+ calcium
Al3+ aluminum
Na + sodium
3. A anion has the same name as the element name with adding –ide to the end.
Examples: Cl - chloride
S2- sulfide
P3- phosphide
Binary Ionic Compounds (Type I monatomic cations & anions)
Section 2.8
Naming Simple Compounds
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Common Simple Cations and Anions
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1. The cation is always named first and the anion second.
2. A simple cation takes its name from the name of the element.
3. A simple anion is named by taking the first part of the element name (the root) and adding –ide.
Rules for Naming Type I Ionic Compounds
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Naming Simple Compounds
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• Examples:
KCl Potassium chloride
MgBr2 Magnesium bromide
CaO Calcium oxide
Binary Ionic Compounds (Type I)
Section 2.8
Naming Simple Compounds
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Ionic Compounds
Now let us put it all together:
Na3N
Cation: sodium
Anion: nitride
Compound: Sodium nitride
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Ionic Compounds
BaO
Cation: barium
Anion: oxide
Compound: barium oxide
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Naming Binary Ionic Compounds (Type I)
SUMMARY - Name the metal first, then the nonmetal with ending changed to -ide.
Examples:
NaCl sodium chloride
ZnI2 zinc iodide
Al2O3 aluminum oxide
KCl Potassium chloride
MgBr2 Magnesium bromide
CaO Calcium oxide23
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Exercise
What is the name of the compound SrBr2?
a) strontium bromine
b) sulfur bromide
c) strontium dibromide
d) strontium bromide
Section 2.8
Naming Simple Compounds
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Learning Check Complete the names of the following type I binary compounds:
Na3N sodium ________________
KBr potassium ________________
Al2O3 aluminum ________________
MgS _________________________
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Section 2.8
Naming Simple Compounds
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Solution Complete the names of the following binary compounds:
Na3N sodium nitride
KBr potassium bromide
Al2O3 aluminum oxide
MgS magnesium sulfide
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Binary Ionic Compounds (Type II)
• Metals in these compounds can form more than one type of positive charge.
• Charge on the metal ion must be specified.
• Roman numeral indicates the charge of the metal cation.
• Transition metal cations usually require a Roman numeral.
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Naming Simple Compounds
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• Metals in these compounds form more than one type of positive charge.
• Charge on the metal ion must be specified.• Roman numeral indicates the charge of the metal
cation.• Transition metal cations that form 2 or more
positive ions require a Roman numeral.
Binary Ionic Compounds (Type II)
1+ or 2+ ____________________ 2+ or 3+
Cu+, Cu2+ Fe2+, Fe3+
copper(I) ion iron(II) ion
copper (II) ion iron(III) ion
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Common Type II Cations
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1. The cation is always named first and the anion second.
2. Because the cation can assume more than one charge, the charge is specified by a Roman numeral in parentheses.
Rules for Naming Type II Ionic Compounds
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• Examples:
CuBr Copper(I) bromide
FeS Iron(II) sulfide
PbO2 Lead(IV) oxide
Binary Ionic Compounds (Type II)
Section 2.8
Naming Simple Compounds
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Binary Ionic Compounds (Type II)
Use a roman number after the name of a metal that forms two or more ions (note compound is neutral)
Example:
FeCl3 (Fe3+) iron (III) chloride
CuCl (Cu+ ) copper (I) chloride
SnF4 (Sn4+) tin (IV) fluoride
PbCl2 (Pb2+) lead (II) chloride
Fe2S3 (Fe3+)iron (III) sulfide
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Exercise
What is the name of the compound CrO2?
a) chromium oxide
b) chromium(II) oxide
c) chromium(IV) oxide
d) chromium dioxide
Section 2.8
Naming Simple Compounds
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Exercise
What is the correct name of the compound that results from the most stable ion for sulfur and the metal ion that contains 24 electrons?
a) iron(III) sulfide
b) chromium(II) sulfide
c) nickel(III) sulfate
d) iron(II) sulfide
Section 2.8
Naming Simple Compounds
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Learning Check Complete the names of the following binary
compounds with variable metal ions:
FeBr2 iron (_____) bromide
Cu2O copper (_____) oxide
SnCl4 ___(_____ ) ______________
Fe2O3 ________________________
CuS ________________________35
Section 2.8
Naming Simple Compounds
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Solution Complete the names of the following binary
compounds with variable metal ions:
FeBr2 iron ( II ) bromide
Cu2O copper ( I ) oxide
SnCl4 tin (IV) chloride
Fe2O3 iron (III) oxide
CuS copper (II) sulfide36
Section 2.8
Naming Simple Compounds
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Learning Check
Name the following compounds:A. CaO
B. SnCl4
C. Co2O3
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Solution Name the following compounds:
A. CaO calcium oxide
B. SnCl4 tin(IV) chloride
C. Co2O3 cobalt (III) oxide
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• Polyatomic ions are charged entities composed of several atoms bound together.
• They have special names and must be memorized. (see Table 2.5 on pg. 62 in text).
• Examples of compounds containing polyatomic ions:
NaOH Sodium hydroxide
Mg(NO3
)2
Magnesium nitrate
(NH4
)2
SO4
Ammonium sulfate
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Naming Simple Compounds
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Names of Common Polyatomic Ions
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• Naming ionic compounds containing polyatomic ions follows rules similar to those for binary compounds. Ammonium acetate
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NaOH Sodium hydroxide
Mg(NO3)2 Magnesium nitrate
(NH4)2SO4 Ammonium sulfate
FePO4 Iron(III) phosphate
Examples
Section 2.8
Naming Simple Compounds
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Exercise
What is the name of the compound KClO3?
a) potassium chlorite
b) potassium chlorate
c) potassium perchlorate
d) potassium carbonate