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Covalent Bonding Covalent Bonding and Covalent Nomenclature

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  • Covalent Bonding

    Covalent Bonding and Covalent Nomenclature

  • Covalent bonding sharing of electronsMade of two or more nonmetals!

  • Formed between two nonmetals Electrons are shared by the atomsCovalent Bonds

  • Covalent Bonds

    In a covalent bond, the shared electrons are considered part of the complete outer energy level of both atoms involved.Covalent bonding generally occurs when elements are relatively close to each other on the Periodic Table.When two or more atoms bond covalently, a molecule is formed.

  • single bond shares one pair of electrons

    double bond shares two pairs of electrons

    triple bond shares three pairsof electronsCovalent Bond Sharing

  • Covalent compound formulasExamples: carbon dioxide, carbon tetrachlorideOxidation Number: Unpaired Valence ElectronsNumber of covalent bonds an atom can formHydrogen = 1Oxygen = 2; single and double bondsNitrogen = 3; single, double and triple bondsCarbon = 4 - single, double and triple bonds

  • Lewis Dot StructuresHydrogen chloride formation

  • Lewis Dot StructuresPhosphorus tribromide (PBr3) formation

  • Properties of Covalent MoleculesSolids, liquids, or gases at room temperatureNonconductive as solidsMay dissolve in waterDissolve in nonpolar solvents (hexane or alcohol)Non-conductive when dissolvedLow melting points

  • Learning CheckIndicate whether a bond between the following would be 1) Ionic2) covalent

    ____A. sodium and oxygen____B. nitrogen and oxygen ____C. phosphorus and chlorine____D. calcium and sulfur ____E. chlorine and bromine

  • Polar covalent bondsElectrons are unequally shared. The molecule has an area of positive charge and an area of negative charge.Not symmetricalExamples: H2O(water) and NH3(ammonia)

  • Electrons are equally shared and there is no charge.SymmetricalExamples: CO2(carbon dioxide), CCl4(carbon tetrachloride), O2(oxygen gas)Nonpolar covalent bonds

  • Learning Check Identify the type of bond between the following atoms A. K-N1) nonpolar 2) polar3) ionicB. N-O1) nonpolar2) polar3) ionicC. Cl-Cl1) nonpolar 2) polar3) ionic

  • Naming Binary Molecular CompoundsTwo nonmetalsName each element End the last element in -ideAdd prefixes to show more than 1 atomFor example: Carbon dioxide CO2

  • Prefixes for naming *Mono 1 * Penta5*Di2* Hexa6*Tri3* Hepta7*Tetra4 * Octa8Used to indicate multiplesMono normally omittedException: carbon monoxide

  • Learning Check Fill in the blanks to complete the following names of covalent compounds.CO carbon ______oxideCO2carbon _______________PCl3phosphorus _______chlorideCCl4carbon ________chlorideN2O_____nitrogen _____oxide

  • Learning Check A.P2O51) phosphorus oxide2) phosphorus pentoxide3) diphosphorus pentoxide

    B.Cl2O71) dichlorine heptoxide2) dichlorine oxide3) chlorine heptoxide

  • VSEPR TheoryValence Shell Electron Pair Repulsion

  • VSEPR TheoryPredicts the molecular shape of a bonded moleculeElectrons around the central atom arrange themselves as far apart from each other as possibleUnshared pairs of electrons (lone pairs) on the central atom repel the mostSo only look at what is connected to the central atom

  • Linear2 atoms attached to center atom0 lone pairs

    Bond angle = 180o

    Ex. : BeF2

  • Trigonal Planar3 atoms attached to center atom0 lone pairs

    Bond angle = 120o

    Ex. : AlF3

  • Tetrahedral 4 atoms attached to center atom0 lone pairs

    Bond angle = 109.5o

    Ex. : CH4

  • Bent2 atoms attached to center atom2 lone pairs

    Bond angle = 104.5o

    Ex. : H2O

  • Metallic Bonding

  • Nature of Metallic BondingMetal atoms from latticesThe outer valence shell electrons of each metal atom contribute to a sea of electrons in the lattice

  • Metallic PropertiesHigh thermal and electrical conductivityMalleable- can be hammered into sheetsDuctile- can be drawn into wire