Organic Chemistry I. Organic compounds A. Contain carbon atom(s) and usually come from living things. 1. Exception - CO 2 and CO B. Also contain other major elements of life: H, O, N, S, and P

II. The HONC rule A. These are the four most common elements in living things B. Arrangement of letters in rule tell us the number of bonds the atom needs in order to be stable: 1. Hydrogen forms one chemical bond. 2. Oxygen forms two chemical bonds. 3. Nitrogen forms three chemical bonds. 4. Carbon forms four chemical bonds. What is the stable formula for methane (CH 4 )? Water (H 2 O)?Ammonia (NH 3 )?Carbon dioxide (CO 2 ) O=C=O

III. Writing Chemical Formulas A. Empirical formula - gives the number and kinds of atoms (e.g. ethanol = C 2 H 6 O) B. Structural formula - lines represent chemical bonds (shared electrons) between atoms. ethanol

C. Modified structural Formula - is used to save time, but don’t forget the HONC rule. CH 3 CH 2 OH ethanol

IV. Hydrocarbons A. Simplest organic compounds. B. Made only of carbon and hydrogen C. Contain a lot of stored energy (fuels) D. Insoluble (don’t dissolve) in water E. Form the backbone of most organic molecules; “scaffold" to hang reactive functional groups

V.Common functional groups  Region of organic molecules commonly involved in chemical reactions A. Alcohols (hydroxyl groups) (R-OH) What does the “R” stand for?  Soluble in water  Good fuel source (ethanol) Can you draw structural formula for ethanol (C 2 H 6 O)? CH 3 CH 2 OH

B. Carbonyl Group (aldehydes and ketones) (R-C-R’) 1.Somewhat soluble in water 2.Nail polish remover (acetone) O = aldehyde ketone

C.Organic Acids/Carboxyl Group (R- COOH) 1. Like all acids, they are sour. 2. Many are aromatic (smell). 3. Water soluble CH 3 –C O OH CH 3 CH 2 CH 2 –C O OH H-C O OH R– C O-H O Acetic Acid (Vinegar) Butyric Acid (Sweat) Formic Acid (Bees and Ants)

D.Amine Group (R- NH 2 ) 1. Soluble in water 2. Alkaline (i.e. a proton acceptor) 3. Ammonia derivative methylamine