Chem: VSEPR & Polarity Test

Bond types, electronegativity, molecular Geometry, VSEPR, and Naming compounds

asymmetrial

lack of symmetry in a molecule

bond location

independent of the number of bonds at that location- whether single, double, or triple, its seen as one

bonding pair

electron pair being shared between two atoms

dipole-dipole

force between 2 oppositely-charged ends of 2 polar molecules

electronegativity

relative ability of an atom to attract electrons in a chemical bond

electron affinity

measures the tendency of an atom to acceptan electron

electron domain

the number of lone pairs or bond locations around a particular atom

molecular shape

linear, trigonal planar, bent, tetrahedral, trigonal pyramid, trigonal bipyramid, see saw, T shape, octahedral, square pyramid, square planar

electron geometry

linear, trigonal planar, tetrahedral, trigonal bipyramid, and octahedral

hybridization

concept of mixing 2 atomic orbitals to give rise to a new type of hybridized orbitals

intermolecular forces

london dispersion forces, dipole-dipole, and hydrogen bonding; forces that mediate interactions between molecules

intramolecular forces

force that holds atoms together to form a molecule; covalent, ionic, and metallic

lone pair

pair of valence electrons that aren’t shared with another atom in a covalent bond

polar covalent

0.5-1.7

nonpolar covalent

<0.5

symmetrical

certain parts of a molecule can be interchanged with others without altering it

VSEPR

valence, shell, electron, pair, repulsion; used to find out what the molecule would look like in 3-D

<0.5

nonpolar covalent

0.5-1.7

polar covalent

>1.7

ionic

VSEPR/molecular shapes

1 domain: AX, 1 BP 0 LP, MS: linear, EG: linear, Hybridization: s, angle: 180

2 domains: AX2, 2 BP 0 LP, MS: linear, EG: linear, Hybridization: sp, angle: 180

2 Domains: AXE, 1 BP 1 LP, MS: linear, EG: linear, Hybridization: sp, angle: 180

3 domains: AX3, 3 BP 0LP, MS: trigonal planar, EG: trigonal planar, Hybridization: sp2, angle: 120

AX2E, 2 BP 1 LP, MS: bent, EG: trigonal planar, Hybridization: sp2, angle: 120

AXE2, 1 BP 2 LP, MS: linear, EG: trigonal planar, Hybridization: sp2, angle: 120

4 domains: AX4, 4 BP 0 LP, MS: tetrahedral, EG: tetrahedral, Hybridization: sp3, angle 109.5

AX3E, 3 BP 1 LP, MS: trigonal pyramid, EG: tetrahedral, Hybridization: sp3, angle: 109.5

AX2E2, 2 BP 2 LP, MS: bent, EG: tetrahedral, Hybridization: sp3, angle: 109.5

AXE3, 1 BP 3 LP, MS: linear, EG: tetrahedral, Hybridization: sp3, angle 109.5

characteristics of a covalent bond

state at room temp: gases, liquids, or low-melting solids

solubility: soluble in organic liquids

formation: formed between two nonmetals

conductivity: doesn’t conduct electricity

boiling point: low

determine a symmetrical or asymmetrical molecule

Non polar molecules are symmetric with no unshared electrons. Polar molecules are asymmetric, either containing lone pairs of electrons on a central atom or having atoms with different electronegativities

weakest to strongest intermolecular forces

van der waals, dipole-dipole, hydrogen bonds, ion-dipole and then ion-ion

Percy Julian: compounds discovered & synthesized

physostigmine, drug that treats glaucoma

stigmasterol, bean oil extract used to make steroid

progesterone, sex hormone

hydrocortisone, synthesized and treats arthritis

Percy Julian: key events + places in his life

high school diploma: montgomery, alabama, 1916

college education: depauw Uni, 1920

M.A. degree: Harvard, 1923

Ph.D. in chem: university of Vienna, 1931

Chemistry instructor: Fisk Uni, 1932

Chemistry department head: West Virginia state cell, 1923

Research fellow: DePauw Uni, 1933

Director of research: Chicago, 1936

Julian Lab established: Chicago, 1953

Julian Research Institute: Chicago, 1961