GenChem 2nd Quiz

• Hand Picking: separation method in which the components of a mixture can be separated by just picking them out by hands
• Hand Picking: employed to separate solid particles from other solid particles
• Magnetic separation: process that uses magnets to separate magnetic materials from non-magnetic ones in a mixture
• Filtration: process in which solid particles in a liquid are removed using a filter medium that permits the fluid to pass through but retains the solid particles
• Residue: solid particles that are retained in the filter paper
• Filtrate: clear liquid which passes through the filter paper
• Filter: can also be used to separate solid particles of different sizes
• Decantation: process of separation of liquid from solid and other immiscible

  liquids, by removing the liquid layer at the top from the layer of solid or liquid below
• Distillation: process of separating components of a liquid mixture through selective evaporation and condensation
• Sedimentation: process by which heavier impurities in a liquid, typically water, settle into the bottom of container containing the mixture
• Evaporation: technique that is used in separating a mixture, usually a solution of a solvent and a soluble solid
• Evaporation: solution is heated until the organic solvent evaporates where it turns into gas and mostly leaves behind the solid residue
• Crystallization: process by which solid forms, where the atoms or molecules are highly organized into a structure known as a crystal
• Crystallization occurs in two major steps:

  1. Nucleation
  2. Crystal Growth
• Nucleation: appearance of a crystalline phase from either a supercooled liquid or a supersaturated solvent
• Crystal Growth: the increase in the size of particles and leads to a crystal state
• Crystal growth: major stage of crystallization process and consists the addition of new atoms, ions or polymer strings into the characteristic arrangements of the crystal lattice
• Centrifugation:

  centrifuge: circular motion helps denser components sink to the bottom faster
• Paper chromatography: analytical method used to separate-colored chemicals or substance
• Threshing: mostly done using harvesting of crops
• Threshing: grain is then separated from the stalks and grounded into the floor by beating the dry stalks to shake off the dried grains
• Winnowing: the separation of the mixture is carried out with the help of wind or blowing air
• Kinetic Molecular Theory of Matter: explains the states of matter and is based on the idea that matter is composed of particles that are always in motion
• Postulate 1: all matter is made up of atoms and molecules that act as tiny particles
• Postulate 2: These tiny particles are always in motion
• Postulate 3: at the same temperature, the heavier particles move slower than the lighter particles
• Postulate 4: There are attractive forces exist between molecules
• Intermolecular forces: forces of attraction between molecules/particles
• Intermolecular Forces: become stronger as molecules get closer together
• Intermolecular Forces are strongest in solid
• Intermolecular forces: forces that exists between molecules
• Intramolecular forces: forces that holds atoms together within a molecule
• Types of Intermolecular Forces

  1. Dipole-dipole interactions
  2. Hydrogen bonding
  3. London dispersion forces
• Dipole-dipole Interactions: forces occur when the partially positively-charged part of a molecule interacts with the partially negatively charged part of the neighboring molecule
• Hydrogen Bonding: special kind of dipole-dipole interaction that occurs specifically between a hydrogen atom bonded to either an oxygen, nitrogen or fluorine atom
• Hydrogen Bonding: partially positive end of hydrogen is attracted to the partially negative end of the oxygen, nitrogen, or fluorine of another molecule
• London dispersion forces: under the category of van der Waal forces: these are the weakest of the intermolecular forces and exist between all types of molecules, whether ionic or covalent— polar or nonpolar
• Types of Intramolecular Forces:

  1. Ionic Bond
  2. Covalent Bond
• Ionic bond: formed by the complete transfer of valance electron(s) between atoms
• Covalent Bond: formed by sharing electrons to achieve octet configuration and become more stable