logging in or signing up VESPR Bonding and Shapes aSGuest12743 Download Post to : URL : Related Presentations : Share Add to Flag Embed Email Send to Blogs and Networks Add to Channel Uploaded from authorPOINT lite Insert YouTube videos in PowerPont slides with aS Desktop Copy embed code: (To copy code, click on the text box) Embed: URL: Thumbnail: WordPress Embed Customize Embed The presentation is successfully added In Your Favorites. Views: 650 Category: Education License: All Rights Reserved Like it (2) Dislike it (0) Added: February 10, 2009 This Presentation is Public Favorites: 2 Presentation Description No description available. Comments Posting comment... By: jaydeepc (31 month(s) ago) as well as for my class, could you, please ... Saving..... Post Reply Close Saving..... Edit Comment Close By: kammyb (32 month(s) ago) Great presentation... would love to have a copy for my class. Saving..... Post Reply Close Saving..... Edit Comment Close Premium member Presentation Transcript VSEPR Bonding and Shapes : VSEPR Bonding and Shapes Adapted from: Chemistry, The Central Science, 10th edition Theodore L. Brown, H. Eugene LeMay, Jr., and Bruce E. Bursten Molecular Shapes : Molecular Shapes The shape of a molecule plays an important role in its reactivity. By noting the number of bonding and nonbonding electron pairs we can easily predict the shape of the molecule. What Determines the Shape of a Molecule? : What Determines the Shape of a Molecule? Simply put, electron pairs, whether they be bonding or nonbonding, repel each other. By assuming the electron pairs are placed as far as possible from each other, we can predict the shape of the molecule. Electron Domains (charge centers) : Electron Domains (charge centers) We can refer to the electron pairs as electron charge centres. In a double or triple bond, all electrons shared between those two atoms are on the same side of the central atom; therefore, they count as one electron charge centers. This molecule has four electron charge centers. Valence Shell Electron Pair Repulsion Theory (VSEPR) : Valence Shell Electron Pair Repulsion Theory (VSEPR) “The best arrangement of a given number of electron charge centers is the one that minimizes the repulsions among them.” Electron-Domain Geometries : Electron-Domain Geometries These are the electron-domain geometries for two through six electron domains around a central atom. Electron-Domain Geometries : Electron-Domain Geometries All one must do is count the number of electron domains in the Lewis structure. The geometry will be that which corresponds to that number of electron charge centers. Molecular Geometries : Molecular Geometries The electron- charge centers geometry is often not the shape of the molecule, however. The molecular geometry is that defined by the positions of only the atoms in the molecules, not the lone pairs. Molecular Geometries : Molecular Geometries Within each electron charge center shape, then, there might be more than one molecular geometry. Linear Electron Domain : Linear Electron Domain In this shape, there is only one molecular geometry: linear. NOTE: If there are only two atoms in the molecule, the molecule will be linear no matter what the electron charge centers are. Trigonal Planar Electron Domain : Trigonal Planar Electron Domain There are two molecular geometries: Trigonal planar, if all the electron charge centers are bonding Bent, if one of the charge centers is a nonbonding pair. Nonbonding Pairs and Bond Angle : Nonbonding Pairs and Bond Angle Nonbonding pairs (lone pairs) are physically larger than bonding pairs. Therefore, their repulsions are greater; this tends to decrease bond angles in a molecule. Multiple Bonds and Bond Angles : Multiple Bonds and Bond Angles Double and triple bonds place greater electron density on one side of the central atom than do single bonds. Therefore, they also affect bond angles. Tetrahedral Electron Domain : Tetrahedral Electron Domain There are three molecular geometries: Tetrahedral, if all are bonding pairs Trigonal pyramidal if one is a nonbonding pair Bent if there are two nonbonding pairs Trigonal Bipyramidal Electron Domain : Trigonal Bipyramidal Electron Domain There are two distinct positions in this geometry: Axial Equatorial Trigonal Bipyramidal Electron Domain : Trigonal Bipyramidal Electron Domain Lower-energy conformations result from having nonbonding electron pairs in equatorial, rather than axial, positions in this geometry. Trigonal Bipyramidal Electron Domain : Trigonal Bipyramidal Electron Domain There are four distinct molecular geometries in this domain: Trigonal bipyramidal Seesaw T-shaped Linear Octahedral Electron Domain : Octahedral Electron Domain All positions are equivalent in the octahedral domain. There are three molecular geometries: Octahedral Square pyramidal Square planar Larger Molecules : Larger Molecules In larger molecules, it makes more sense to talk about the geometry about a particular atom rather than the geometry of the molecule as a whole. Larger Molecules : Larger Molecules This approach makes sense, especially because larger molecules tend to react at a particular site in the molecule. Polarity : Polarity In Chapter 8 we discussed bond dipoles. But just because a molecule possesses polar bonds does not mean the molecule as a whole will be polar. Polarity : Polarity By adding the individual bond dipoles, one can determine the overall dipole moment for the molecule. Polarity : Polarity Overlap and Bonding : Overlap and Bonding We think of covalent bonds forming through the sharing of electrons by adjacent atoms. In such an approach this can only occur when orbitals on the two atoms overlap. Overlap and Bonding : Overlap and Bonding Increased overlap brings the electrons and nuclei closer together while simultaneously decreasing electron-electron repulsion. However, if atoms get too close, the internuclear repulsion greatly raises the energy. You do not have the permission to view this presentation. In order to view it, please contact the author of the presentation.
VESPR Bonding and Shapes aSGuest12743 Download Post to : URL : Related Presentations : Share Add to Flag Embed Email Send to Blogs and Networks Add to Channel Uploaded from authorPOINT lite Insert YouTube videos in PowerPont slides with aS Desktop Copy embed code: (To copy code, click on the text box) Embed: URL: Thumbnail: WordPress Embed Customize Embed The presentation is successfully added In Your Favorites. Views: 650 Category: Education License: All Rights Reserved Like it (2) Dislike it (0) Added: February 10, 2009 This Presentation is Public Favorites: 2 Presentation Description No description available. Comments Posting comment... By: jaydeepc (31 month(s) ago) as well as for my class, could you, please ... Saving..... Post Reply Close Saving..... Edit Comment Close By: kammyb (32 month(s) ago) Great presentation... would love to have a copy for my class. Saving..... Post Reply Close Saving..... Edit Comment Close Premium member Presentation Transcript VSEPR Bonding and Shapes : VSEPR Bonding and Shapes Adapted from: Chemistry, The Central Science, 10th edition Theodore L. Brown, H. Eugene LeMay, Jr., and Bruce E. Bursten Molecular Shapes : Molecular Shapes The shape of a molecule plays an important role in its reactivity. By noting the number of bonding and nonbonding electron pairs we can easily predict the shape of the molecule. What Determines the Shape of a Molecule? : What Determines the Shape of a Molecule? Simply put, electron pairs, whether they be bonding or nonbonding, repel each other. By assuming the electron pairs are placed as far as possible from each other, we can predict the shape of the molecule. Electron Domains (charge centers) : Electron Domains (charge centers) We can refer to the electron pairs as electron charge centres. In a double or triple bond, all electrons shared between those two atoms are on the same side of the central atom; therefore, they count as one electron charge centers. This molecule has four electron charge centers. Valence Shell Electron Pair Repulsion Theory (VSEPR) : Valence Shell Electron Pair Repulsion Theory (VSEPR) “The best arrangement of a given number of electron charge centers is the one that minimizes the repulsions among them.” Electron-Domain Geometries : Electron-Domain Geometries These are the electron-domain geometries for two through six electron domains around a central atom. Electron-Domain Geometries : Electron-Domain Geometries All one must do is count the number of electron domains in the Lewis structure. The geometry will be that which corresponds to that number of electron charge centers. Molecular Geometries : Molecular Geometries The electron- charge centers geometry is often not the shape of the molecule, however. The molecular geometry is that defined by the positions of only the atoms in the molecules, not the lone pairs. Molecular Geometries : Molecular Geometries Within each electron charge center shape, then, there might be more than one molecular geometry. Linear Electron Domain : Linear Electron Domain In this shape, there is only one molecular geometry: linear. NOTE: If there are only two atoms in the molecule, the molecule will be linear no matter what the electron charge centers are. Trigonal Planar Electron Domain : Trigonal Planar Electron Domain There are two molecular geometries: Trigonal planar, if all the electron charge centers are bonding Bent, if one of the charge centers is a nonbonding pair. Nonbonding Pairs and Bond Angle : Nonbonding Pairs and Bond Angle Nonbonding pairs (lone pairs) are physically larger than bonding pairs. Therefore, their repulsions are greater; this tends to decrease bond angles in a molecule. Multiple Bonds and Bond Angles : Multiple Bonds and Bond Angles Double and triple bonds place greater electron density on one side of the central atom than do single bonds. Therefore, they also affect bond angles. Tetrahedral Electron Domain : Tetrahedral Electron Domain There are three molecular geometries: Tetrahedral, if all are bonding pairs Trigonal pyramidal if one is a nonbonding pair Bent if there are two nonbonding pairs Trigonal Bipyramidal Electron Domain : Trigonal Bipyramidal Electron Domain There are two distinct positions in this geometry: Axial Equatorial Trigonal Bipyramidal Electron Domain : Trigonal Bipyramidal Electron Domain Lower-energy conformations result from having nonbonding electron pairs in equatorial, rather than axial, positions in this geometry. Trigonal Bipyramidal Electron Domain : Trigonal Bipyramidal Electron Domain There are four distinct molecular geometries in this domain: Trigonal bipyramidal Seesaw T-shaped Linear Octahedral Electron Domain : Octahedral Electron Domain All positions are equivalent in the octahedral domain. There are three molecular geometries: Octahedral Square pyramidal Square planar Larger Molecules : Larger Molecules In larger molecules, it makes more sense to talk about the geometry about a particular atom rather than the geometry of the molecule as a whole. Larger Molecules : Larger Molecules This approach makes sense, especially because larger molecules tend to react at a particular site in the molecule. Polarity : Polarity In Chapter 8 we discussed bond dipoles. But just because a molecule possesses polar bonds does not mean the molecule as a whole will be polar. Polarity : Polarity By adding the individual bond dipoles, one can determine the overall dipole moment for the molecule. Polarity : Polarity Overlap and Bonding : Overlap and Bonding We think of covalent bonds forming through the sharing of electrons by adjacent atoms. In such an approach this can only occur when orbitals on the two atoms overlap. Overlap and Bonding : Overlap and Bonding Increased overlap brings the electrons and nuclei closer together while simultaneously decreasing electron-electron repulsion. However, if atoms get too close, the internuclear repulsion greatly raises the energy.