Transcript
Chapter 7:
Language of Chemistry
IUPAC
• The International Union of Pure and Applied Chemistry, IUPAC, has set rules for naming compounds.
• IUPAC set the rules for the naming and classification of inorganic compounds in 1940.
• These rules, referred to as IUPAC nomenclature, are still in use today.
Classification of Compounds
Ionic Compounds
• Binary ionic compounds contain two
elements: one metal and one
nonmetal.
• NaCl and AlCl3 are binary ionic compounds.
• Ternary ionic compounds contain
three elements, at least one metal and
one nonmetal.
• KNO3 and Al(NO3)3 are ternary ionic compounds.
Molecular Compounds
• Binary molecular compounds
contain two elements and both are
nonmetals.
• Some examples of binary molecular
compounds are ammonia, NH3; methane, CH4;
carbon dioxide, CO2; and tetraphosphorous
trisulfide, P4S3.
Aqueous Acids
• An aqueous solution is produced when a compound dissolves in water. It is indicated by the symbol (aq).
• A binary acid is an aqueous solution of a compound containing hydrogen
and one other nonmetal. HF (aq) is a binary acid.
• A ternary oxyacid is an aqueous
solution of a compound containing
hydrogen, oxygen, and one other nonmetal. HNO3(aq) is a ternary oxyacid.
Classification of Ions
• An ion is an atom or group of atoms with a charge.
• A positively charged ion is called a cation.
• A negatively charged ion is called an anion.
• A group of atoms bound together that has an overall
charge is called a polyatomic anion.
Metals Form Positive Ions
Metals form positive ions (cations)
• by a loss of their valence electrons.
• with the electron configuration of the
nearest noble gas.
• that have fewer electrons than protons.
Group 1A metals ion 1+
Group 2A metals ion 2+
Group 3A metals ion 3+
Monoatomic Cations
• Cations are named for the parent atom followed by the
word “ion.”
• Na+ is named “sodium ion.”
• Al3+ is named “aluminum ion.”
• This rule applies for metals that usually form one ion.
This includes the main group metals along with Ag+,
Zn2+, and Cd2+. Exceptions include tin and lead.
Metals that Form
Multiple Ions
If a metal can form more than
one cation, it is named by the
parent followed by the charge in
Roman numerals in parentheses,
ending with the word “ion.”
Metals that Form Multiple Ions
Cation Stock System
Cr2+ chromium (II)
Cr3+ chromium (III)
Mn2+ manganese (II)
Fe2+ iron (II)
Fe3+ iron (III)
Co2+ cobalt (II)
Co3+ cobalt (III)
Ni2+ nickel (II)
Cu1+ copper (I)
Cu2+ copper (II)
Sn2+ tin (II)
Sn4+ tin (IV)
Hg22+ mercury (I)
Hg2+ mercury (II)
Pb2+ lead (II)
Pb4+ lead (IV)
Non-metals form Negative Ions
Nonmetals form negative ions (anions)
• by gaining electrons.
• form negatively charged ions with 3-, 2-, or 1- charges.
• Non-metals ions are named by changing the end of their
element name with the suffix –ide.
• N3− is the nitride ion.
• O2− is the oxide ion.
• Br− is the bromide ion.
Ion Charges
Some Ionic Charges
I-
Learning Check
A. The symbol for the magnesium ion is
1) Mg1+. 2) Mg2+. 3) Mg2- .
B. For aluminum to achieve a noble gas configuration, the change of electrons requires a
1) loss of 3e-. 2) gain of 3e-. 3) a gain of 5e-.
C. The symbol for the aluminum ion is
1) Al3+. 2) Al3-. 3) Al+.
D. The number of valence electrons in sulfur is
1) 4e-. 2) 6e-. 3) 8e-.
E. The ionic charge of sulfur is
1) 2+. 2) 2-. 3) 4-.
Ionic Compounds
Ionic compounds
• consist of positive
and negative ions.
• have attractions called ionic bonds between
positively and negatively charged ions.
• have high melting and boiling points.
• are solid at room temperature.
NaCl formation
reaction video
An ionic formula
• consists of positively and negatively charged ions. • is neutral.
M+ + X- MX
Cation + Anion Ionic compound
• the symbol of the metal (cation) is written first followed
by the symbol of the nonmetal (anion).
Ionic Formulas
Ionic Formulas
Examples:
1). Na+ and Cl– form NaCl or sodium chloride.
2). Mg2+ and Cl– form MgCl2 or magnesium chloride.
3). Na+ and S2– form Na2S or sodium sulfide.
Select the correct formula for each of the following ionic compounds.
A. Al3+ and Cl-
1) AlCl3 2) AlCl 3) Al3Cl
B. Mg2+ and N3-
1) MgN 2) Mg2N3 3) Mg3N2
C. K+ and I-
1). K2I 2). KI2 3). KI
Learning Check
Naming Binary Ionic Compounds
Naming FeCl2
To name FeCl2
1. Determine the charge of the cation using the charge of the anion (Cl-).
2. Name the cation by the element name and add a
Roman numeral in parenthesis to show its charge.
Fe2+ = iron(II)
3. Write the anion with an ide ending.
FeCl2 = iron(II) chloride
Naming Cr2O3
To name Cr2O3
1. Determine the charge of cation from the anion (O2-).
2. Name the cation by the element name and add a
Roman numeral in parenthesis to show its charge.
Cr3+ = chromium(III)
3. Write the anion with an ide ending.
chromium(III) oxide = Cr2O3
Learning Check
Select the correct name for each.
A. Fe2S3
1) iron sulfide
2) iron(II) sulfide
3) iron(III) sulfide
B. CuO
1) copper oxide
2) copper(I) oxide
3) copper(II) oxide
Learning Check
What is the correct formula for each of the following?
A. Copper(I) nitride
1) CuN 2) CuN3 3) Cu3N
B. Lead(IV) oxide
1) PbO2 2) PbO 3) Pb2O4
Name the following ionic compounds.
A. MgI2
B. CaO
C. FeBr2
D. K3P
E. CuCl
Learning Check
A polyatomic ion
• is a group of atoms.
• has an overall ionic charge.
Some examples of polyatomic ions are
NH4+ ammonium OH− hydroxide
NO3−
nitrate NO2
− nitrite
CO32− carbonate PO4
3− phosphate
HCO3− hydrogen carbonate
(bicarbonate)
Polyatomic Ions
Polyatomic anions that contain one or more elements combined
with oxygen are called oxyanions.
• end in ate.
NO3− nitrate PO4
3− phosphate
• with one oxygen less end in ite.
NO2− nitrite PO3
3− phosphite
• with hydrogen attached use the prefix hydrogen (or bi).
HCO3− hydrogen carbonate (bicarbonate)
HSO3− hydrogen sulfite (bisulfite)
Polyatomic Ions
The positive ion is named first followed by the name of the
polyatomic ion.
NaNO3 sodium nitrate
K2SO4 potassium sulfate
Fe2(CO3) 3 iron(III) carbonate
NH4Cl ammonium chloride
Naming Ternary Ionic Compounds
Match each formula with the correct name.
A. MgS 1) magnesium sulfite
MgSO3 2) magnesium sulfate
MgSO4 3) magnesium sulfide
B. Ca(ClO3)2 1) calcium chlorate
CaCl2 2) calcium chlorite
Ca(ClO2)2 3) calcium chloride
Learning Check
Learning Check
Name each of the following compounds:
A. Mg(NO3)2
B. Cu(ClO3)2
C. PbO2
D. Fe2(SO4)3
E. Ba3(PO3)2
Select the correct formula for each.
A. aluminum nitrate
1) AlNO3 2) Al(NO)3 3) Al(NO3)3
B. copper(II) nitrate
1) CuNO3 2) Cu(NO3)2 3) Cu2(NO3)
C. iron(III) hydroxide
1) FeOH 2) Fe3OH 3) Fe(OH)3
D. tin(IV) hydroxide
1) Sn(OH)4 2) Sn(OH)2 3) Sn4(OH)
Learning Check
Learning Check
Write the chemical formula for each of the following compounds:
A. calcium carbonate
B. chromium (III) bromide
C. mercury (I) oxide
D. ammonium chlorite
E. silver nitrate
Critical Thinking: Potassium
• Potassium is an extremely reactive element (its violent reaction
with water is pictured below).
• How can such a reactive element (with water) be essential for
human life?
• Good sources of potassium include fish, meat, fruit, dark
vegetables, and nuts.
Binary Molecular Compounds
• Binary molecular compounds are composed of two
nonmetal elements.
• A molecule is the simplest representative particle of a
binary molecular compound.
• IUPAC has set the following order for writing the
elements in a binary molecular compound:
• C, P, N, H, S, I, Br, Cl, O, and F
Naming Molecular Compounds To name molecular compounds
• STEP 1: First element in formula is named first.
• STEP 2: Second element is named next using the prefixes in table 4.12 to denote the number of atoms present and an ide ending.
• STEP 3: Prefixes on 1st element are used EXCEPT mono.
ex. CO is carbon monoxide
Table 4.12
Examples
1. BF3 = boron trifluoride
2. NO = nitrogen monoxide
3. N2O5 = dinitrogen pentoxide
4. P4S3 = tetraphosphorus trisulfide
Common names always used:
H2O = water
NH3 = ammonia
Select the correct name for each compound.
A. SiCl4 1) silicon chloride
2) tetrasilicon chloride
3) silicon tetrachloride
B. P2O5 1) phosphorus oxide
2) phosphorus pentoxide
3) diphosphorus pentoxide
C. Cl2O7 1) dichlorine heptoxide
2) dichlorine oxide
3) chlorine heptoxide
Learning Check
Write the correct formula for each of the following.
A. phosphorus pentachloride
B. dinitrogen trioxide
C. sulfur hexafluoride
Learning Check
Learning Check
Identify each compound as ionic or covalent and give its
correct name.
A. SO3
B. BaCl2
C. (NH4)3PO4
D. Cu2CO3
E. N2O4
Learning Check
Write the formulas for the following.
A. calcium nitrate
B. boron trifluoride
C. aluminum carbonate
D. dinitrogen tetroxide
E. copper(I) phosphate
Binary Acids
• A binary acid is an aqueous solution of a compound
containing hydrogen and a nonmetal.
• The formula of an acid always begins with H:
• HF (aq)
• Binary acids are named by using the prefix hydro- before
the element stem and adding the suffix -ic acid.
• HF (aq) is hydrofluoric acid.
• HI (aq) is hydroiodic acid.
Ternary Oxyacids
• Ternary oxyacids are aqueous solutions of a compound
containing hydrogen and an oxyanion.
• If the acid is derived from an oxyanion ending in -ate, the
suffix is changed to -ic acid.
• HNO3 (aq) is nitric acid (from NO3-, nitrate ion).
• If the acid is derived from an oxyanion ending in -ite, the
suffix is changed to -ous acid.
• HNO2 (aq) is nitrous acid (from NO2-, nitrite ion).
Oxyanions and Oxyacids
Below is an example of ternary oxyacid and ternary
compound naming.
Ternary Oxyacid Ternary Compound
HClO hypochlorous acid NaClO sodium hypochlorite
HClO2 chlorous acid NaClO2 sodium chlorite
HClO3 chloric acid NaClO3 sodium chlorate
HClO4 perchloric acid NaClO4 sodium perchlorate
Learning Check
Provide the name of the acid.
1. HCN =
2. H2S =
3. H3PO4 =
4. HNO2 =
5. H2SO3 =
6. HClO4 =
7. HClO =
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