When there are six electron groups around the central atom and two are lone

When there are six electron groups around the central

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When there are six electron groups around the central atom, and two are lone pairs, the result is called a square planar shape . The bond angles between equatorial positions are 90°.
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Practice Problem on Molecular Geometry and Electron Groups
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Using VSEPR to Predict Molecular Geometries The steps: 1. Draw the Lewis structure. 2. Determine the number of electron groups around the central atom. 3. Classify each electron group as a bonding or lone pair, and count each type. Remember, multiple bonds count as one group. 4. Determine the shape and bond angles.
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Practice Problem on Predicting Molecular Geometries Predict the molecular geometry and bond angle of ClNO Predict the molecular geometry of ICl 4
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Representing Three-Dimensional Shapes on Paper is difficult. How to draw a 3-D representation of molecule on paper: By convention, the central atom is put in the plane of the paper. Put as many other atoms as possible in the same plane and indicate with a straight line . For atoms in front of the plane, use a solid wedge . For atoms behind the plane, use a hashed wedge .
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Illustrations of Molecular Geometries of Molecules Using 3-D Notations
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Multiple Central Atoms and Their Geometries Many molecules have larger structures with many interior atoms. Think of them as having multiple central atoms. For multiple center molecules: Each center atom has a designated shape. The shape around the: N atom is trigonal pyramidal Left C is tetrahedral Right C is trigonal planar O is bent
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Practice Problem on Predicting Molecular Geometries for Multi-Centered Molecules Predict the geometry about each interior atom in each: Make a sketch of each of the molecules CH 3 CH 2 CH=CHCH 2 CH 3
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Polarity of Molecules For a molecule to be polar, it must have the following: Polar bonds Electronegativity difference Bond dipole moments—measured An unsymmetrical shape Vector addition Polarity affects the intermolecular forces of attraction. Example: Boiling points and solubilities Like dissolves like Nonbonding pairs affect molecular polarity, a strong pull in its direction.
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Molecule Polarity The bond between the H atom and Cl atom in HCl molecule is polar. The bonding electrons are pulled toward the Cl end of the molecule because Cl is more electronegative (EN) than the H atom. The net result is a polar molecule.
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Molecule Polarity The bond between the C atom and O atoms in CO 2 molecule is polar. The bonding electrons are pulled toward the O ends of the molecule equally because O is more electronegative (EN) than the C atom. The net result is a nonpolar molecule.
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Molecule Polarity The bond between the O atom and H atoms in H 2 O molecule is polar. Both sets bonding electrons are pulled toward the O end of the molecule equally because O is more electronegative (EN) than the H atom.
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