Organic Chemistry - Chapter 01 Glossary Words

Front 1

acid-dissociation constant (Ka)

Back 1

the equilibrium constant for the reaction of the acid with water to generate H3)+ (p23)

The negative logarithm of Ka is expressed as kPa

Front 2

Arrhenius Acid

Back 2

acid which dissociates in water to give H30+

Front 3

Arrhenius Base

Back 3

base which dissociates in water to give -OH

Front 4

Bronsted-Lowry Acid

Back 4

Acid - substance which is a proton (H+) donor

Front 5

Bronsted-Lowry Base

Back 5

Base - substance which is a proton (H+) acceptor

Front 6

Lewis Acid

Back 6

Acid - an electron-pair acceptor (electrophile)

Front 7

Lewis Base

Back 7

Base - an electron-pair donor (nucliophile)

Front 8

conjugate acid

Back 8

the acid that results from protonation of a base (p23)

Front 9

conjugate base

Back 9

the base that results from loss of a proton from an acid (p25)

Front 10

covalent bonding

Back 10

bonding that occurs by the sharing of electrons in the region between two nuclei (p7)

Front 11

single bond

Back 11

A covalent bond that involves the sharing of one pair of electrons (p8)

Front 12

double bond

Back 12

A covalent bond that involves the sharing of two pairs of electrons (p8)

Front 13

triple bond

Back 13

A covalent bond that involves the sharing of three pairs of electrons (p8)

Front 14

curved-arrow formalism

Back 14

A method of drawing curved arrows to keep track of electron movement from necleophile to electrophile (or within a molecule) during the course of a reaction. (p31)

Front 15

degenerate orbitals

Back 15

orbitals with identical energies (p4)

Front 16

dipole moment (mu)

Back 16

A measure of the polarity of a bond (or a molecule), proportional to the product of the charge separation times the bond length. (p10)

Front 17

electron density

Back 17

the relative probability of finding an electron in a certain region of space. (p3)

Front 18

electronegativity

Back 18

A measure of an element's ability to attract electrons. Elements with higher electronegativities attract electrons more strongly. (p10)

Front 19

electrophile

Back 19

an electron-pair acceptor (Lewis Acid) (p29)

Front 20

electrostatic potential map (EPM)

Back 20

a computer-calculated molecular representation that uses colors to show the charge distribution in a molecule. In most cases, the EPM uses red to show electron-rich regions (most negative electrostatic potential) and blue to show electron-poor regions (pomst positive electrostatic potential) The intermediate colors organge, yellow, and green show regions with intermediate electrostatic potentials. (p10)

Front 21

empirical formula

Back 21

the ratios of atoms in a compound (p20)

Front 22

formal charges

Back 22

a method for keeping track of charges, showing what charge would be on an atom in a particular Lewis structure (p11)

Front 23

Hund's rule

Back 23

when there are two or more unfilled orbitals of the same energy (degenerate orbitals), the lowest-energy configuration places the electrons in different orbitals (with parallel spins) rather than paired in the same orbital (p6)

Front 24

ionic bonding

Back 24

bonding that occurs by the attraction of oppositely charged ions. Ionic bonding usually results in the formation of a large, three-dimensional crystal lattice. (p7)

Front 25

isotopes

Back 25

Atoms with the same number of protons but different numbers of neutrons: atoms of the same element but with different atomic masses (p3)

Front 26

Lewis structure

Back 26

a structural formula that shows all valence electrons with the bonds symbolized by dashes (--) or by pairs of dots and nonbonding electrons symbolized by dots. (p7)

Front 27

line-angle formula (skeletal structure, stick figure)

Back 27

a shorthand structural formula with bonds represented by lines. Carbon atoms are implied wherever two lines meet or a line begins or bends. Atoms other than C and H are drawn in, but hydrogen atoms are not shown unless they are on an atom that is drawn. Each carbon atom is assumed to have enough hydrogens to give it four bonds. (p19)

Front 28

lone pair

Back 28

a pair of nonbonding electrons (p7)

Front 29

molecular formula

Back 29

the number of atoms of each element in one molecule of a compound.

the *empirical formula* simply gives the ratios of atoms of the different elements. For example, the molecular formula of glucose is C6H12O6. Its empirical formula is CH2O. Neither the molecular formula nor the empirical formula gives structural information (p20)

Front 30

node

Back 30

a region in an orbital with zero electron density (p4)

Front 31

nodal plane

Back 31

a flat (planar) region of space with zero electron density (p4)

Front 32

nonbonding electrons

Back 32

valence electrons that are not used for bonding. A pair of nonbonding electrons is often called a lone pair

Front 33

nucleophile

Back 33

an electron-pair donor (Lewis base) (p29)

Front 34

octet rule

Back 34

atoms generally form bonding arrangements that give them filled shells of electrons (noble-gas configurations). For the second row elements, this configuration has eight valence electrons. (p6)

Front 35

orbital

Back 35

an alowed energy state for an electron bound to a nucleus; the probability function that defines the distribution of electron density in space. Teh Pauli exclusion principle states that up to two electrons can occupy each orbital if their spins are paired. (p31)

Front 36

organic chemistry

(New definition)

Back 36

The chemistry of carbon compounds
(p1)

Front 37

organic chemistry

(Old definition)

Back 37

The study of compounds derived from living organisms and their natural products. (p1)

Front 38

pH

Back 38

a measure of the acidity of a solution, defined as the negative logarithm (base 10) of the H3O+ concentration:

pH = -log[H3O+]

(p22)

Front 39

polar covalent bond

Back 39

a covalent bond in which electrons are shared unequally. A bond with equal sharing of electrons is called a nonpolar covalent bond. (p9)

Front 40

resonance hybrid

Back 40

a molecule or ion for which two or more valid Lewis structures can be drawn, differeing only in the placement of the balence electrons. These Lewis structures are called reasonance forms or resonance structures. Individual resonance forms do not exist but we can estimate their relative energies. The more important (lower energy) structrues are called major contributors and the less important (higher energy) structures are called minor contributors. When a charge is spread over two or more atoms by resonance, it is said to be delocalized and the molecule is said to be resonance stabilized.

Front 41

structural formulas

Back 41

a *complete structural formula* (such as a Lewis structure) shows all the atoms and bonds in the molecule. A *condensed structural formula* shows each central atom along with the atoms bonded to it. A *line-angle formula* (sometimes called a *skeletal structure* or *stick figure*) assumes that there is a carbon atom wherever two lines meet or a line begins or ends. ((p17)

Front 42

valence

Back 42

the number of bonds an atom usually forms (p9)

Front 43

valence electrons

Back 43

those electrons that are in the outermost shell (p6)

Front 44

Vitalism

Back 44

the belief that syntheses of organic compounds require the presence of a "vital force" (p1)