Solids & Crystal Structures

the structure of solids crystalline solidsAmorphous solids Are those whose particles molecules or ions have an ordered arrangement Are those whose particles are randomly arranged and have no ordered long range structure Like rubber crystalline solids Molecular solidsIonic solidsNetwork covalent solids Metallic solids Are those whose constituent particules are molecules held together by intermolecular forces like ice, sucrose Whose particules are ions NaCl Whose atoms are linked by covalent bonds in three dimension Diamond graphite In which the structural units are electrons and cations like Ag, Fe

Crystal Structures Unit cellis the smallest repeating unit of the crystal Coordination number is the number of atoms which with a given atom is in contact Basic unit cells of crystal lattices Cubic Tetragonal Orthorhombic Monoclinic Triclinic Rhombohedral Hexagonal

cubic Hexagonal

Unit Cells in the Cubic Crystal System

Coordination number Number of atom per unit cell 2 4 1

Atomic radius in cubic cells 2r = s 4r = s √2 4r = s √3

Silver metal crystallize in a face centered cubic cell with edge of the unit cell having a length 0.407nm. Calculate the atomic radius of silver

The ionic radii of Na + and Cl - are 99 and 181 pm respectively what is the length of the unit cell of NaCl (unit cell of NaCl is given in the picture)

Solutions Homogeneous mixtures are called solutions. Solventsolute is the component present in greatest amount or determines the state of solution exist is a component present in a lesser quantity and it is said to be dissolved in the solvent. concentrated solution A solution is one that has a relatively large quantity of dissolved solute dilute solutionA solution has only small quantity of solute electrolytenonelectrolyte Substances whose water solutions conduct electricity are called electrolyte

SoluteSolventSolutionexample Gas Air GasLiquid soda (CO 2 in H 2 O) Liquid ethanol in water SolidLiquid Saline solution (NaCl in H 2 O) GasSolid H 2 in Pd Solid 14 karat gold (Ag in Au)

Mass of solute Percent by mass = x 100 Mass of solution Volume of solute Percent by volume = x 100 Volume of solution Mass of solute Mass / volume percent = x 100 (gr/100ml) Volume of solution Solution Concentrations

Number of moles of solute Molarity = Number of liters of solution Number of moles of solute Molality = Number of kilograms of solvent Moles of component i Mole fraction = total moles of all solution components Parts per million (ppm), Parts Per Billion(ppb) mg solute  g solute 1 ppm = ppb = kg solution kg solution

question. A solution has a density of 1.235g/ml and contains 90.0% glycerol C3H8O3 and 10% H2O by mass. Determine a- the molarity of C3H8O3 b- the molarity of H2O c- mole fraction of C3H8O3 d- mole percent of H2O e- the molality of H2O

question. A solution has a density of 1.235g/ml and contains 90.0% glycerol C3H8O3 and 10% H2O by mass. Determine a- the molarity of C3H8O3 b- the molarity of H2O c- mole fraction of C3H8O3 d- mole percent of H2O e- the molality of H2O