Lesson 1: Organic Chemistry

Hydrocarbons Crash course Nomenclature Crash course (functional groups) Alkenes and alkynes Crash course

Properties of Organic compounds Section 1A Properties of Organic compounds

Are compounds containing the element carbon… Organic compounds Are compounds containing the element carbon… Propane

…that bond to one another to form chains, rings, and networks. Organic compounds …that bond to one another to form chains, rings, and networks. Propane

…that bond to one another to form chains, rings, and networks. Organic compounds …that bond to one another to form chains, rings, and networks. Iso-butane

…that bond to one another to form chains, rings, and networks. Organic compounds …that bond to one another to form chains, rings, and networks. Benzene

Organic compounds Notice that carbon forms the skeleton of the molecule

Organic compounds usually have C in front of their formulas C4H10 C6H6 Iso-butane C3H8 Propane C6H6 Benzene

A Carbon atom always forms a total of four bonds with other atoms. This creates a characteristic shape: Double bond 1 1 4 4 Methane CH4 2 3 3 2 1 4 3 2 Tetrahedral shape ethene C2H4

( big and sticky forces) Organic compounds usually form… Covalent bonds with nonpolar molecules They are usually Gases, liquids OR waxy solids with low melting points Remember? Weak London IM forces ( big and sticky forces)

Organics are usually Not soluble in water (oily or waxy) un-likes don’t dissolve

Organics are usually Non-electrolytes (except acids-COOH … which are weak) Acetic acid HC2H3O2 CH3COOH(aq)

Many organic reactions require a catalyst. Usually have Slow reactions With high activation energies Many organic reactions require a catalyst.

Hydrocarbons are the simplest: ORGANIC COMPOUNDS Hydrocarbons are the simplest: contain only carbon and hydrogen.

Clues: Molecular? All gainers/nonmetals Molecular? nonpolar nonpolar Nonpolar – weak IM forces Combustion is combining with Oxygen? So it contains C and H?

What rule does carbon follow when bonding? Carbon always forms how many bonds?

Homologous series Section B

Organics are sometimes grouped by Homologous series: 1 carbon Methane 2 carbons ethane 3 carbons propane 4 carbons butane Series of compounds with similar structures

Homologous series: Members vary by adding more carbons to the chain Methane 2 carbons ethane 3 carbons propane 4 carbons butane Members vary by adding more carbons to the chain

Homologous series: Will have similar properties 1 carbon Methane 2 carbons ethane 3 carbons propane 4 carbons butane Will have similar properties Properties vary slightly from one member to the next

Homologous series: 1 carbon Methane 2 carbons ethane 3 carbons propane 4 carbons butane These are in the series of hydrocarbons called the ALKANES

Both are useful as fuels 3 carbons propane 4 carbons butane Both are useful as fuels

HOMOLOGOUS SERIES Members differ by 1 C and 2 H’s: CH2

HOMOLOGOUS SERIES Members differ by 1 C and 2 H’s: CH2

Homologous series: ALKANES Contain all single bonds between carbon atoms in the chain.

Series 1: The Alkanes

Homologous series: ALKANES have the general formula CnH2n+2 where “n” equals the number of carbon atoms in the chain.

Homologous series: ALKANES member’s names always ends in “ane”.

Homologous series: ALKANES The number of carbons in the chain determines the prefix to put in front of the name ending.

Homologous series: ALKANES CnH2(n) + 2 C4H10 C4H2(4) + 2 But ane 4 C’s = But-

C1H4 = CH4 methane C2H6 ethane C3H8 propane C4H10 butane Etc.

CH4 methane C2H6 ethane C3H8 propane

M-ust E-very PR-efect B-e PE-rfect Meth Eth Prop But Pent

pentane Pent = 5 C ane = alkane CnH2n+2 C5H2(5)+2 C5H12 Reference table Q shows the general formula and structure for the series tested on the regents exam. Pent = 5 C ane = alkane CnH2n+2 C5H2(5)+2 C5H12

pentane Pent = 5 C ane = alkane CnH2n+2 C5H2(5)+2 C5H12

Ethane Propane C3H8 C2H6 C2H2(2)+2 H H H C C H H H Heptane C7H16

So what is the name of this compound? A “methyl” group Address: #2 Carbon C4H10 propane So what is the name of this compound? It has the same formula as butane But it has a different structure 2-methyl propane Its an Isomer (I-som-er)

ISOMERS Compounds that have the same molecular formula C4H10 Compounds that have the same molecular formula but have a different structure.

ISOMERS Isomers will have different physical and chemical properties.

ISOMERS C4H10 Also, the greater the number of carbons in a chain, the more isomers possible.

ISOMERS C4H10 Two isomers of butane

Three isomers of pentane n-pentane Di-methyl propane Three isomers of pentane Methyl butane

IUPAC RULES FOR NAMING COMPOUNDS Name the longest carbon chain. Number the carbons in the chain so side groups can be “addressed”: (direction uses lowest whole numbers possible) Determine the names of side groups. carbon groups start with a prefix, then add “yl”. if more than one of the same side group appears, prefixes telling the number of side groups are used (di, tri, tetra, etc.).

1. Name the Longest Carbon Chain: 3 C’s so it is a Propane.

2. Number the Longest Carbon chain for identifying bond location 3 1 3 2 1 2. Number the Longest Carbon chain for identifying bond location Propane

3. Group Comes Off 2nd Carbon so its address is 2-. OR 2 3 1 3 2 1 3. Group Comes Off 2nd Carbon so its address is 2-. 2- Propane

4. Side Group has 1 Carbon so it is “Methyl” group so . . . 2 4. Side Group has 1 Carbon so it is “Methyl” group so . . . 2- Methyl Propane

2-methyl propane (it is an isomer of butane).

TRY THESE: n-PENTANE “normal” pentane

TRY THESE: Count and name the longest chain. 1 2 3 What side groups and their addresses? 2, 2 DIMETHYL PROPANE

TRY THESE: Still 2,2 dimethyl propane 1 2 3 Notice: you could number the chain vertically? Still 2,2 dimethyl propane

Name this: A chain of 4 C’s?

Name this:

Name this:

Hint: move a carbon from the end to the middle of the chain Make a 4 carbon chain with a 1 carbon group: “methyl butane”

Un-Saturated compounds Section C

SATURATED COMPOUNDS Hydrocarbons containing only single carbon-carbon bonds – (have all “bond sites” occupied) the members of the alkane series. Butane is saturated with hydrogen

Unsaturated = are missing H’s from the chain Has a double bond between C atoms Missing H’s here C3H6 Prop- ene

Unsaturated = are missing H’s from the chain These are all unsaturated Can you spot the empty bond sites?

UNSATURATED COMPOUNDS Hydrocarbons containing double and/or triple carbon-carbon bonds. Involves two or three shared pairs of electrons between carbon atoms. Members of the alkene and alkyne series. When naming unsaturated hydrocarbons, the placement of the double or triple bond must be identified.

Homologous series: ALKENES Contain one double bond between carbon atoms in the chain. Have the general formula CnH2n. Member’s names always ends in “ene”. First member is ethene. C2H4

Homologous series: ALKYNES Contain one triple bond between carbon atoms in the chain. Have the general formula CnH2n–2. Member’s names always ends in “yne”. Number address of triple bond. First member is ethyne. C2H2

1 propene 1 butyne 2 butyne Name These Compounds: 1 2 3 1 2 3 4 1 2 3

Name this: 5 carbon chain? Double bond b/t 2nd and 3rd C?

Name this: ↑ Is this the 5th or 2nd carbon?

Name this:

One more:

Hint: draw it and see if you need a double or triple bond so each C has four bonds

Hint: see above hint