Molecular Polarity and Its Properties - PowerPoint Presentation

 Electronegativity – The ability of an atom to attract electrons in a bond. (Higher electronegativity = stronger pull on electrons) Valence Electrons – The outermost electrons of an atom, which are involved in bonding. Dipole – A molecule with two poles (one slightly positive, one sl...

 Electronegativity – The ability of an atom to attract electrons in a bond. (Higher electronegativity = stronger pull on electrons) Valence Electrons – The outermost electrons of an atom, which are involved in bonding. Dipole – A molecule with two poles (one slightly positive, one slightly negative) due to uneven electron sharing. Covalent Bond – A type of bond where atoms share electrons to become stable. Miscible – Two liquids that can mix completely, like water and alcohol. Immiscible – Two liquids that do not mix, like oil and water. Molecular polarity means how charge is distributed in a molecule.  Occurs Type of Bond What It Is Result Examples Between Sodium Creates Chloride Electrons are Metals and Ionic Bond oppositely (NaCl), transferred nonmetals charged ions Magnesium Oxide (MgO) Strong bonds Water (H₂O), Covalent Electrons are between Nonmetals Carbon Dioxide Bond shared nonmetals (CO₂) Atoms with No partial Nonpolar Electrons are similar Methane (CH₄), charges on Covalent shared equally electronegativi Oxygen (O₂) atoms ties Atoms with Electrons are Partial positive Water (H₂O),  Bond Shape Description Example Angle Atoms are arranged Carbon Dioxide Linear 180° in a straight line (CO₂) Three atoms around Boron Trifluoride Trigonal Planar a central atom in a 120° (BF₃) plane Four atoms around a Tetrahedral central atom forming 109.5° Methane (CH₄) a tetrahedron Five atoms around a Trigonal central atom, three Phosphorus 90°, 120° Bipyramidal in a plane and two Pentachloride (PCl₅) above and below Six atoms around a Sulfur Hexafluoride Octahedral central atom forming 90° (SF₆) an octahedron Similar to trigonal Bent/Angular planar but with lone < 120° Water (H₂O) pairs which of the following substances below will most likely mix with each Substance Substance other? Will Mix? 1 2 Water Ethanol (H₂O) (C₂H₅OH) Sodium Water Chloride (H₂O) (NaCl) Oil Water (Various) (H₂O) Vinegar Water (CH₃COOH Intermolecular forces of attraction are the forces that hold molecules together in a substance. London Dispersion Forces (LDF) Weakest force found in all molecules. Caused by temporary shifts in electron movement. Example: Oxygen gas (O₂), noble gases like helium (He). Dipole-Dipole Forces Happens between polar molecules (molecules with positive and negative sides). Stronger than LDF but weaker than hydrogen bonding. Example: Water (H₂O) and acetone. Hydrogen Bonding A special strong dipole-dipole force when hydrogen bonds with F (fluorine), O (oxygen), or N (nitrogen). Makes water molecules stick together, giving water its unique properties. Example: Water (H₂O), DNA structure, and alcohol. Ion-Dipole Forces Strongest intermolecular force, occurs between ions and polar molecules. Helps dissolve ionic compounds in water. Example: Salt (NaCl) dissolving in water.