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NAMING AND WRITING CHEMICAL COMPOUNDS. OUTLINE. IUPAC BOHR DIAGRAMS FOR ATOMS TYPES OF CHEMICAL BONDS MOLECULAR COMPOUNDS TYPES SIMPLE COVALENT COMMON NAME IONIC COMPOUNDS SIMPLE IONIC MULTIVALENT POLYATOMIC/COMPLEX HYDRATED IONIC ACIDS. IUPAC.
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OUTLINE • IUPAC • BOHR DIAGRAMS FOR ATOMS • TYPES OF CHEMICAL BONDS • MOLECULAR COMPOUNDS • TYPES • SIMPLE COVALENT • COMMON NAME • IONIC COMPOUNDS • SIMPLE IONIC • MULTIVALENT • POLYATOMIC/COMPLEX • HYDRATED IONIC • ACIDS
IUPAC • International Union of Pure and Applied Chemists • This is a global organization that sets the standards in chemistry. • One job of the IUPAC is to give compounds SYSTEMIC NAMES.
BOHR DIAGRAMS FOR ATOMS • Bohr diagrams, also called ENERGY LEVEL DIAGRAMS, are a means of drawing atoms in a 2-D manner. • Keep in mind that atoms are actually 3-D, and there are more complex representations of atoms. • Bohr models always include the NUCLEUS and the ELECTRON ENERGY LEVELSof an atom. • LINK
BOHR DIAGRAMS . . . • There are 3 types of SUBATOMIC PARTICLES found in the atom: • PROTONS (p+) • Positively charged particles with a significant mass • Atomic Number = Number of Protons • ELECTRONS (e-) • Negatively charged particles with an insignificant mass • Number of Electrons = Number of Protons • NEUTRONS (no) • Neutral particles with a significant mass • Number of neutrons = Atomic Mass – Atomic Number
BOHR DIAGRAMS . . . • NUCLEUS • Center of the atom, contains protons and neutrons • The atomic mass is concentrated here • ELECTRON ENERGY LEVELS • Particular areas around the nucleus where electrons are likely to be found • Electrons DO NOT exist BETWEEN energy levels • 3 LEVELS: • FIRST LEVEL (Closest to Nucleus) 2 e- • SECOND LEVEL 8 e- • THIRD LEVEL (Outermost) 8 e-
BOHR DIAGRAMS . . . • VALENCE LEVEL • DEFINITION: Outermost energy level of an atom • Electrons in this level are called VALENCE ELECTRONS • Atoms with FULL valence shells are STABLE, meaning they will not bond with other atoms in normal conditions. • The atoms of Group 18, the Noble Gases, have full valence levels. • Atoms that do not have full electron energy levels are unstable and must GAIN, LOSE, or SHARE electrons to become stable.
BOHR DIAGRAMS . . . • ATOMIC NUMBER • Located in the top of each element box on the periodic table. • ATOMIC NUMBER = # OF PROTONS • ATOMIC MASS (MOLAR MASS) • Located in the bottom of each element box on the periodic table. • Round it off for calculations. • ATOMIC MASS = # OF PROTONS + # OF NEUTRONS
BOHR DIAGRAMS . . . • EXAMPLE: DRAW BOHR DIAGRAMS FOR: • Li – lithium atom • ATOMIC # = _____________ • ATOMIC MASS = _____________ • # p+ = ________________________ • # e- = ________________________ • # no = ________________________
BOHR DIAGRAMS . . . • EXAMPLE: DRAW BOHR DIAGRAMS FOR: • Ne – neon atom • ATOMIC # = _____________ • ATOMIC MASS = _____________ • # p+ = ________________________ • # e- = ________________________ • # no = ________________________
BOHR DIAGRAMS . . . • EXAMPLE: DRAW BOHR DIAGRAMS FOR: • S – sulfur atom • ATOMIC # = _____________ • ATOMIC MASS = _____________ • # p+ = ________________________ • # e- = ________________________ • # no = ________________________
TYPES OF CHEMICAL BONDS • CHEMICAL BONDS • DEFINITION: • A force of attraction between atoms. • There are 2 TYPES of Chemical bonds • Covalent • Ionic
TYPES OF CHEMICAL BONDS • COVALENT BONDS • AKA: molecular bonds • “co” – together/sharing , “valent” – outer shell • DEFINITION: • A SHARING of ELECTRONS between 2 atoms • BETWEEN a two or more NONMETALS • Solutions of covalently bonded substances are NON-ELECTROLYTIC.
TYPES OF CHEMICAL BONDS • IONIC BOND • DEFINITION: • A TRANSFER of ELECTRONS between two atoms • BETWEEN a METAL and a NONMETAL • Solutions of ionic bonded substances are ELECTROLYTIC. • COMPOUNDS consist of atoms or ions of two or more elements bonded together.
MOLECULAR COMPOUNDS • Forms when 2 or more NONMETALS share electrons in COVALENT BONDS. • 2 TYPES: • BINARY Molecular Compounds • TRIVIAL NAME Molecular Compounds
BINARY MOLECULAR COMPOUNDS • Also called SIMPLE molecular compounds. • Binary Molecular Compounds use IUPAC prefixes: • We will write these prefixes in the following table.
Given Molecular Formula, Write Name • RULES: • Write NAMES of elements, with the 2nd element ending in “-ide”. • Add PREFIXES to indicate HOW MANY ATOMS of each element. • Do NOT use the prefix “mono” for the 1st element, only with the 2nd element.
Given Formula, Write Name EXAMPLE • N2O4 ________________________ • P2O5 ________________________ • CCl4 ________________________
GIVEN MOLECULAR NAME, WRITE FORMULA • RULES: • Write ELEMENT SYMBOLS for each element in the compound. • Use the PREFIX in the name to determine NUMBER OF ATOMS, and write that number as a SUBSCRIPT next to the symbol (no subscript for 1 atom).
Given Name, Write Formula EXAMPLE • carbon monoxide ____________ • triphosphoruspentabromide ____________ • sulfur hexafluoride ____________
TRIVIAL NAME Molecular Compounds • Also called COMMON NAME molecular compounds. • There are SOME molecular compounds that go by their COMMON NAMES, and we must memorize these names.
IONS • RECALL: • AS mentioned earlier, atoms other than the NOBLE GASES are unstable, and need to GAIN, LOSE, or SHARE ELECTRONS to become more stable. • If they SHARE electrons, this forms a COVALENT BOND to another atom. • If they LOSE or GAIN electrons, atoms become IONS and form IONIC BONDS with other atoms. • OCTET RULE • Atoms that have an octet of valence electrons are STABLE and UNREACTIVE.
WHAT IS AN ION? • Ions are charged atoms that have lost or gained electrons to achieve the valence configurations of a noble gas. • TWO TYPES: • CATIONS: • POSITIVE ions that are formed from a LOSS of electrons. • It has more PROTONS than ELECTRONS and therefore has a net POSITIVE charge. • METALS form cations. • MEMORY TOOL: t in “cation” resembles a “+” sign • EXAMPLE: lithium ionLi+ 1+ charge
ANIONS: • NEGATIVE ions that are formed from a GAIN of electrons. • It has more ELECTRONS than PROTONS and therefore has a net NEGATIVE charge. • change the ending of the name of anions to -ide • NONMETALS form anions. • MEMORY TOOL: A Negative ION • EXAMPLE: fluoride ionF- 1- charge • LINK
BOHR DIAGRAMS FOR IONS • METALS • ATOMS of METALS will LOSE electrons to become CATIONS. • ATOMS with 1, 2, or 3 VALENCE electrons will LOSE these electrons to form 1+, 2+, or 3+ ions respectively. • GROUP 1 ATOMS – ALKALI • 1valence electrons(s) (will lose 1 to become stable) • 1 + ion • GROUP 2 ATOMS – ALKALINE EARTH • 2valence electrons(s) (will lose 2 to become stable) • 2 + ion • GROUP 13 ATOMS • 3valence electrons(s) (will lose 3 to become stable) • 3 + ion
BOHR DIAGRAMS FOR IONS • NONMETALS • ATOMS of NONMETALS will GAIN electrons to become ANIONS. • ATOMS with 5,6, or 7 VALENCE electrons will GAIN these electrons to form 3-, 2-, or 1- ions respectively. • GROUP 15 ATOMS • 5valence electrons(s) (will gain 3 to become stable) • 3 - ion • GROUP 16 ATOMS • 6valence electrons(s) (will gain 2 to become stable) • 2 - ion • GROUP 17 ATOMS - HALOGENS • 7valence electrons(s) (will gain 1 to become stable) • 1 - ion • GROUP 18 ATOMS - NOBLE GASES • FULL outer valence levels
TO DRAW: • Note that in BOHR DIAGRAMS for IONS, electron numbers have changed. • Here is a quick equation for calculating the number of electrons: • # e- = #p+ - charge
DRAW A BOHR DIAGRAM FOR: • A sodium ATOM and a sodium ION
DRAW A BOHR DIAGRAM FOR: • A chlorine ATOM and a chloride ION
IONIC COMPOUNDS • Form when at least 1 METAL AND 1 NONMETAL transfer electrons in an IONIC BOND. • Metals will become CATIONS and LOSE electrons and nonmetals will become ANIONS and GAIN electrons. • These ions, with opposite charges, attract and form IONIC BONDS. • Unlike covalent bonds, these bonds are not “ACTUAL BONDS,” but forces of attraction between oppositely charged ions. • They stay together in a CRYSTAL LATTICE.
IONIC COMPOUNDS • Example: NaCl (Draw on your sheet) Cl- Cl- Cl- Cl- Na+ Na+ Na+ Cl- Cl- Na+ Na+ Cl- Na+ Na+ Cations are surrounded by anions and vice versa Also refer to Figure 4, p. 189
IONIC COMPOUNDS • Example: NaCl
IONIC COMPOUNDS • 3 TYPES: • Binary Ionic Compounds • SIMPLE • MULTIVALENT • Polyatomic Ionic Compounds • Hydrated Ionic Compounds
BINARY IONIC COMPOUNDS • “Binary” • Only 2 types of ions involved. • SIMPLE IONIC COMPOUNDS • Simple ionic compounds are composed of a metal ion (+) and a nonmetal ion(-). • GIVEN FORMULA, WRITE NAME • RULES: • Write the name of the CATION before the ANION (Be positive before being negative ) • Change the ending of the ANION name to “-ide” • Do not use CAPITALS, Do not use PREFIXES!
SIMPLE IONIC COMPOUNDS • EXAMPLE: • MgBr2 _________________________________ • KCl _________________________________ • Na2S _________________________________ • Mg3P2 _________________________________ • Ba3N2 _________________________________ • WHAT’S WRONG WITH THE FOLLOWING NAMES FOR BaS? • barium sulfur ____________________________ • Barium Sulfide ____________________________ • barium sulfuride ____________________________
SIMPLE IONIC COMPOUNDS • GIVEN NAME, WRITE FORMULA • RULES: • Write element symbols. • Look up the ION CHARGE on the periodic table. • Use the “crossover” method to determine the numbers of each ion in the compound. • Ion ratios are always in the lowest common multiple. • Ion charges must add up to “zero” overall.
SIMPLE IONIC COMPOUNDS EXAMPLE: • sodium bromide _____________________ • barium iodide ___________________
SIMPLE IONIC COMPOUNDS EXAMPLE: • magnesium oxide _____________________ • aluminum oxide ___________________