Organic Chemistry Basics

ORGANIC CHEMISTRY BASICS

OVERVIEW  There are several main branches of chemistry: Analytical, Physical, Environmental, Inorganic, Organic, Biochemistry….  Organic chemistry focuses on the compounds that contain “carbon backbones” – over 6,000,000 natural and synthetic compounds…and growing every day  “Carbon backbones” are inherent to things that are or once were living o Examples: petroleum, medicines, plastics, plants and animals…... (including YOU!!) For example, the Prudhoe Bay field on the North Slope of Alaska is the largest field ever discovered in the Western Hemisphere. The ultimate recovery of crude oil from this field is anticipated to be about 10 billion barrels, which is sufficient to supply the current needs of the United States for less than two years, but only one such field was discovered in the West in more than a century of exploration. Furthermore, drilling activity has not halted the steady decline of North American crude oil reserves that began during the 1970s.

TO KNOW YOUR CARBON IS TO LOVE YOUR CARBON  The Octet Rule says that everybody wants to have 8 outer shell electrons, Carbon has only 4 (it’s glass is both half empty and half full) – so instead of giving or taking electrons (Ionic bonding) it SHARES electrons – A.K.A Covalent Bonding A.K.A Molecular compounds  When Carbon shares electrons to fulfill it’s outer shell – it needs to share with other atoms to get 4 more electrons – so it needs to make 4 bonds.  We write Lewis Dot Structures to show the sharing of electrons, and thus formation of bonds between atoms in Covalent compounds  Example of Lewis Dot structure for C and for H

A shared pair of electrons between 2 atoms is a bond, and the 2 dots representing the bond can be replaced by a line connecting the atoms – this is called a Structural formula H H H C H H C H H H

Carbon bonds contain potential energy (actually all bonds contain energy) – the beauty of petroleum is that the long chains of carbons connected to one another contain a lot of bonds – and therefore a lot of potential energy

Carbon chain lengths effect physical properties of the compounds – check out how the intermolecular forces between carbon compounds with increasing numbers of carbons effects the boiling points of these compounds – Your turn pg. 175) Where do the building blocks of synthetic organic compounds come from? Fractional distillation and products (Figure 9 pg. 169 & 174) You Decide pg. 173 – uses of fractions World’s petroleum reserves distribution (Figure 2 pg. 158) (You decide pg. 164) You Decide A.1 – What types of things are made of petroleum Summary Q’s A pg. 165-6