Week1 Flashcards
Chemistry of compounds that contain the element carbon
Organic chemistry
Key structural features of living organisms
Carbon atom
What was the first period of organic chemistry all about?
The general advancement of organic chemistry
• The vital force theory (vitalism)
Organic compounds were only those that came from living organisms, living things could synthesize organic compounds through the intervention of vital force
Who synthesize urea?
Friedrich Wöhler (1828)
What was the second period of organic chemistry all about?
August Kekulé, Archibald Scott Couper, and Alexander M. Butlerov
- they suggested that each substance are defined by specific arrangement of atoms
What are the two central ideas of structural theory
- The atoms of molecules are held together by bonds and that atoms has the same number of bonds with its most stable compounds. The measure of this ability is called valence.
- The carbon atoms are the key structural features and that concept is used to predict the large molecules containing network of carbon atoms.
It is generally forms of four bonds
Tetravalent
Ex: Carbon
It is generally form of three bonds
Trivalent
Ex: Nitrogen
It is generally form of two bonds
Divalent
Ex: Oxygen
It is generally form of only one bond
Monovalent
Ex: Hydrogen
Halogens ( F, Cl, Br, I)
What is stereochemistry
It is the study of the relative spatial arrangement of atoms that form the structure of molecules and their manipulation
Molecules having the same molecular structure and sequence of bonded atoms but differing three dimensional orientation of atoms in space
Stereoisomers
What is compounds
These are made up of elements combined in different proportions
What is elements
These are made up of atoms
What consist of atoms
It is consist of a dense, positively charged nucleus containing protons and neutrons and is surrounding cloud of electrons
It is atoms of the same element with different numbers of neutrons and does different A
Isotopes
It is weighted average mass in atomic mass unit of an element’s naturally occurring isotopes
Atomic mass/ atomic weight
It is the most important shell
Valence shell
It is the outermost shell
Valence shell
The electrons of this shell are the ones that an atom uses in making chemical bonds
Valence shell
The tendency for an atom to achieve a configuration where its valence shell contains eight electrons
Octet rule
It is formed by the transfer of one or more electrons from one atom to another atom to create ions
Ionic (electrovalent) bonds
It is formed when atoms share electrons
Covalent bonds
(Ionic character)
EN diff <0.5
Covalent bond
(Ionic character)
0.5 - 2.0
Polar covalent bond
Two major types of bonds
Ionic (electrovalent) bond
Covalent bond
Atoms may gain or lose electrons and form charge particles called
Ions
What is electronegativity?
It is a measure of the ability of an atoms to attract electrons
What is the most electronegative element?
Fluorine
What is the least electronegative element?
Cesium
It feature relatively pure covalent bonds
Homonuclear diatomic molecules
Types of covalent bond
Polar covalent bond
Nonpolar covalent bond
Coordinate covalent bond
Exist between identical atoms, electrically uniform, and the sharing of electrons is equal
Nonpolar covalent bond
Exist between unlike atoms and the electrons are shared unequally
Polar covalent bond
Is the withdrawal of electrons toward oxygen
Induction
Causes the formation of partial positive and partial negative charges
Induction
Induction is symbolized by the Greek symbol
Delta
Coordinate covalent bonds also known as
Dative or coordinate bond
It exist when one of the 2 atoms bonded supports all of the shared electrons
Coordinate covalent bond
Is a graphical representation of the electron distribution around atoms
Lewis structure
It is used to predict the number and type of bonds that may be formed around an atom as well as the geometry of a molecule
Lewis structure
Two atoms are held by one electron pair
Single bond
Two atoms sharing two electron pairs
Double bond
Two atoms sharing three electron pairs
Triple bond
It is the special ability of carbon atoms to form bond with another carbon
Catenation
Synthesis of urea
Ammonium cyanate decomposes into ammonia and cyanic acid and these two reacts reversibly to form urea
