Organic Lec Module 2

• 3 structural formula

  displayed/expanded formula, condensed formula, skeletal/line formula
•  By convention, a single straight line connecting the atomic symbols is used to represent a single (two-electron) bond, two such lines to represent a 2 double (four-electron) bond, and three lines a triple (six-electron) bond. representations of compounds by these symbols are called

  structural formulas
• It is used to show how the electrons are arranged around individual atoms in a molecule. Electrons are shown as "dots" or for bonding electrons as a line between the two atoms. The goal is to obtain the "best" electron configuration, i.e. the octet rule and formal charges need to be satisfied.

  displayed/expanded formula
• The bonds to each carbon are omitted, but each distinct structural unit (group) is written with subscript numbers designating multiple substituents, including the hydrogens. It also show the order of atoms like a structural formula but are written in a single line to save space and make it more convenient and faster to write out. This formula are also helpful when showing that a group of atoms is connected to a single atom in a compound.

  condensed formula
• Are used around the group of atoms to show they are together.

  parentheses
• Are used to write carbon and hydrogen atoms more efficiently by replacing the letters with lines. It also helps show structure and order of the atoms in a compound making the advantages and disadvantages similar to structural formulas. 

  line angle formulas
• What are the 4 types of condensed formulas

  grouped, omit horizontal bonds, omit vertical and horizontal bonds, compressed with parenthesis
• The simplest, whole-number ratio of elements in a compound

  empirical formula
• The actual number of atoms of each element in a molecule

  molecular formula
• The minimal detail for an unambiguous structure

  structural formula
• The relative placing of atoms and the bonds between them

  displayed formula
• The carbon skeleton and functional groups only

  skeletal formula
• The building block of hydrocarbons in structural organic chemistry

  tetravalent carbon atom
• The two-electron bond, which is illustrated by the carbon-hydrogen bonds in methane or ethane and the carbon-carbon bond in ethane, is called 

  single bond
• Is usually shown to mimic the bond angles and steric effect depicted in other models

  zig-zag pattern
• What are the 3D graphical structures

  valence-shell electron-pair repulsion (VSEPR) model, ball and stick model, space filling model
• It can predict the structure of nearly any molecule or polyatomic ion in which the central atom is a nonmetal, as well as the structures of many molecules and polyatomic ions with a central metal atom. 

  VSEPR model
• The premise of the _ is that electron pairs located in bonds and lone pairs repel each other and will therefore adopt the geometry that places electron pairs as far apart from each other as possible. This theory is very simplistic and does not account for the subtleties of orbital interactions that influence molecular shapes.

  VSEPR theory
• Are three-dimensional models where atoms are represented by spheres of different colors and bonds are represented by sticks between the spheres. Particular atoms are associated with different colors, for example, black is usually used to represent carbon and white to represent hydrogen.

  ball and stick model
• It is made with truncated balls held together with snap fasteners are used widely to determine the possible closeness of approach of groups to each other and the degree of crowding of atoms in various arrangements.

  space filling model
• IUPAC stands for

   International Union of Pure and Applied Chemistry
• In the medical field, most drugs have three names

  systematic name, generic name, trade name
• Are compounds with the same molecular formula but different structures

  isomers
• Two types of isomerism

  structural and stereo
• It is also called constitutional isomers, are isomers that vary in the bonding attachments of atoms. 

  structural isomers
• What are the 3 types of structural isomers

  chain, positional, functional
• Same molecular formula but the way their carbon atoms are joined together differ from isomers to isomers

  chain
• Same carbon skeleton and the same functional group but differ from each other in the location of the functional group or in the carbon chain

  positional
• Baring different functional groups

  functional
• Are isomers with the same bonding attachments of atoms but different spatial orientations.

  stereoisomers
• What are the 2 types of stereo isomers

  geometrical and optical
• Have the same condensed structural formula but differ due to the arrangement of their atom space

  geometrical
• Are two compounds which contain the same number and kinds of atoms and bonds but different spatial arrangement of the atom

  optical
• Geometric isomers, also called _, are stereoisomers in which atoms or groups of atoms display orientation differences around a double bond or ring.

  cis and trans isomers
• Optical Isomers, also called _, are isomers that are identical in structure except where they differ as mirror images, mirror images that are not superimposable.

  enantiomers
• Have identical physical constants, such as melting points, boiling points, density, refractive index, viscosity, etc., but are said to be optically active since they can be distinguished from each other by their ability to rotate the plane of polarised light in opposite directions. 

  enantiomers
• A mixture of enantiomers in equal proportions is optically inactive and is called a 

  racemic mixture

• Enantiomers that rotate the plane of polarized light to the right are called_ (prefixed with +)

  dextrorotary
• The ones which rotate to the left are called _  (prefixed with -)

  levorotatory