Chem175 1st Edition Lecture 11 Outline of Last Lecture I. Last Lecture: VocabularyII. ExamplesOutline of Current Lecture III. Quick Review: Vapor Pressure, Boiling PointIV. Classification of Solidsa. Types of Crystalline Solidsi. Unit Cells of Crystalline SolidsCurrent LectureCh. 12 – Liquids and SolidsQuick Review:Vapor pressure is the pressure that the water vapor exerts when the condensation reaction and the vaporization reaction are at equilibrium.Boiling Point is the temperature at which the vapor pressure is equal to the pressure of the surrounding atmosphere. The normal Boiling Point occurs when the vapor pressure of the liquid equals the atmospheric pressure.If we lower the vapor pressure in a closed container with heated (but not boiling water) we can cause boiling to occur. This happens, because the pressure above the water is equal to the vapor pressure and the water molecules can escape intothe air.If we increase the pressure placed on ice we can cause the ice to melt more quickly. This happens, because as we increase the pressure the water molecules become more closely packed together and will liquefy. Liquid water is denser than ice.Solids:Classifications: 1amorphous OR 2crystalline1. Amorphous solids are solids that have no long range structure. In other words, they do not have repeating structures. Amorphous solids are less common than crystalline solids. (Usually certain glasses and plastics are amorphous.)2. Crystalline solids are solids that have long range structure.Types of crystals: 1ionic 2network 3molecular 4metallic1. Ionic crystals are made up of anions and cations bound together by ionic bonds. (ex. NaCl)These notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.2. Network/covalent crystals are crystals made up of covalent bonds. (ex. quartz)3. Molecular crystals are held together by intermolecular forces. (ex. ice, sugar)4. Metallic crystals are held together by a sea of electrons. These elections are not fixed to a certain atom, but the electrons move around the structure. Thisis possible for any element from the S-block or D-block.Metallic crystals can take to the form of close packed solids. In this model,the molecules are treated as hard spheres.A coordination number is the number of nearest neighbors each atom of the close packed structure is touching.Types of close packed solids:1. Hexagonal packing: -every other layer is in the same position-each atom touches 3 molecules above, 3 molecules below and 6 molecules on the same plane (6 = hexagonal)-co-ordination number: 12 (=3+3+6)2. Cubic packing:-every 3 layers are in the same position-each atom touches 4 molecules above, 4 molecules below and 4 molecules on the same plane (4 = cubic)-co-ordination number: 12 (=4+4+4)Unit cells are the smallest repeating structure in a crystal structure. They are rectangular shaped.Fractions of atoms may be put in a unit cell.There are 14 possible unit cells (aka. Bravais Lattices).-this class will only cover three of them.1. Primitive: 18 of an atom in each corner of the cellTotal: 18×8=1 atom2. Face-Centered Cubic:18of an atom in each corner12of an atom on each faceTotal: (18× 8)+(12×6)=4 atoms3. Body-Centered Cubic:18of an atom in each corner1 atom in the middleTotal: (18× 8)+1=2