i chemical bonding. chemical bond attractive force between atoms or ions that binds them together...
TRANSCRIPT
- Slide 1
- I Chemical Bonding
- Slide 2
- Chemical Bond attractive force between atoms or ions that binds them together as a unit bonds form in order to decrease potential energy (PE) increase stability
- Slide 3
- COMPOUND Ternary Compound Binary Compound 2 elements more than 2 elements NaNO 3 NaCl
- Slide 4
- ION Polyatomic Ion Monatomic Ion 1 atom 2 or more atoms NO 3 - Na +
- Slide 5
- IONIC COVALENT Bond Formation Type of Structure Solubility in Water Electrical Conductivity Other Properties e - are transferred from metal to nonmetal high yes (solution or liquid) yes e - are shared between two nonmetals low no usually not Melting Point crystal lattice true molecules TYPES OF BONDS Physical State solid liquid or gas odorous
- Slide 6
- electron sea METALLIC Bond Formation Type of Structure Solubility in Water Electrical Conductivity Other Properties Melting Point TYPES OF BONDS Physical State e - are delocalized among metal atoms very high yes (any form) no malleable, ductile, lustrous solid
- Slide 7
- IONIC BONDS
- Slide 8
- IONIC BONDING - CRYSTAL LATTICE
- Slide 9
- Covalent Bonding - True Molecules Diatomic Molecule
- Slide 10
- METALLIC BONDING - ELECTRON SEA
- Slide 11
- BOND POLARITY Most bonds are a blend of ionic and covalent characteristics. Difference in electronegativity determines bond type.
- Slide 12
- BOND POLARITY Electronegativity Attraction an atom has for a shared pair of electrons. higher e - neg atom - lower e - neg atom +
- Slide 13
- BOND POLARITY Electronegativity Trend (p. 151) Increases up and to the right.
- Slide 14
- BOND POLARITY Nonpolar Covalent Bond e - are shared equally symmetrical e - density usually identical atoms
- Slide 15
- ++ -- Polar Covalent Bond e - are shared unequally asymmetrical e - density results in partial charges (dipole)
- Slide 16
- Nonpolar Polar Ionic
- Slide 17
- BOND POLARITY Examples: Cl 2 HCl NaCl 3.0-3.0=0.0 Nonpolar 3.0-2.1=0.9 Polar 3.0-0.9=2.1 Ionic
- Slide 18
- Chemical Bond attractive force between atoms or ions that binds them together as a unit bonds form in order to decrease potential energy (PE) increase stability
- Slide 19
- I LEWIS DIAGRAMS Molecular Structure
- Slide 20
- RULE Remember Most atoms form bonds in order to have 8 valence electrons.
- Slide 21
- Hydrogen 2 valence e - Groups 1,2,3 get 2,4,6 valence e - Expanded octet more than 8 valence e - (e.g. S, P, Xe) Radicals odd # of valence e - A. OCTET RULE Exceptions: F B F F H O H N O Very unstable!! F F S F F
- Slide 22
- B. DRAWING LEWIS DIAGRAMS Find total # of valence e -. Arrange atoms - singular atom is usually in the middle. Form bonds between atoms (2 e - ). Distribute remaining e - to give each atom an octet (recall exceptions). If there arent enough e - to go around, form double or triple bonds.
- Slide 23
- B. DRAWING LEWIS DIAGRAMS CF 4 1 C 4e - = 4e - 4 F 7e - = 28e - 32e - F F C F F - 8e - 24e -
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- B. DRAWING LEWIS DIAGRAMS BeCl 2 1 Be 2e - = 2e - 2 Cl 7e - = 14e - 16e - Cl Be Cl - 4e - 12e -
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- B. DRAWING LEWIS DIAGRAMS CO 2 1 C 4e - = 4e - 2 O 6e - = 12e - 16e - O C O - 4e - 12e -
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- C. POLYATOMIC IONS To find total # of valence e - : Add 1e - for each negative charge. Subtract 1e - for each positive charge. Place brackets around the ion and label the charge.
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- C. POLYATOMIC IONS ClO 4 - 1 Cl 7e - = 7e - 4 O 6e - = 24e - 31e - O O Cl O O + 1e - 32e - - 8e - 24e -
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- C. POLYATOMIC IONS NH 4 + 1 N 5e - = 5e - 4 H 1e - = 4e - 9e - H H N H H - 1e - 8e - - 8e - 0e -
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- C. POLYATOMIC IONS OH - 1 O 6e - = 6e - 1 H 1e - = 1e - 7e - O H + 1e - 8e - - 8e - 0e -
- Slide 30
- D. RESONANCE STRUCTURES Molecules that cant be correctly represented by a single Lewis diagram. Actual structure is an average of all the possibilities. Show possible structures separated by a double-headed arrow.
- Slide 31
- D. RESONANCE STRUCTURES O O S O O O S O O O S O n SO 3
- Slide 32
- I MOLECULAR GEOMETRY
- Slide 33
- VSEPR THEORY Valence Shell Electron Pair Repulsion Theory Electron pairs orient themselves in order to minimize repulsive forces.
- Slide 34
- VSEPR THEORY Types of e - Pairs Bonding pairs - form bonds Lone pairs - nonbonding e - Lone pairs repel more strongly than bonding pairs!!!
- Slide 35
- VSEPR THEORY Lone pairs reduce the bond angle between atoms. Bond Angle
- Slide 36
- DETERMINING MOLECULAR SHAPE Draw the Lewis Diagram. Tally up e - pairs on central atom. double/triple bonds = ONE pair Shape is determined by the # of bonding pairs and lone pairs. Know the 8 common shapes & their bond angles!
- Slide 37
- COMMON MOLECULAR SHAPES 2 total 2 bond 0 lone LINEAR 180 BeH 2
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- COMMON MOLECULAR SHAPES 3 total 3 bond 0 lone TRIGONAL PLANAR 120 BF 3
- Slide 39
- COMMON MOLECULAR SHAPES 3 total 2 bond 1 lone BENT