Site hosted by Angelfire.com: Build your free website today!

Chemsitry Review #5

Chemistry Review #5

11/25 Book 7-1

- Carbon is unique among atoms because it forms lone- chain and ring compounds with other carbons

Allotrope- one of a number of different molecular or crystalline forms of an element

Isomers- same number and type of atoms arranged in different ways

Covalent network solid- a solid composed of atoms covalently bonded in a network in two or three dimensions (ex. Graphite and diamond)

- Carbon usually forms covalent bonds

- Carbon compounds are comparatively unreactive

- Most organic compounds contain carbon

Hydrocarbons- the simplest organic compounds containing only Hydrogen and Carbon

- Alkanes- simplest- carbons have only single bonds

- Alkenes- contain at least one double bond with carbons. More reactive

- Alkynes- contain at least on triple bond. Most reactive

Cycloalkane- hydrocarbon with ring structure containing only single bonds

Benzene- 6- carbon ring with alternating double and single bonds, indicating delocalized electrons. Reacts like alkane due to stability. The shorthand abbreviation is a circle inscribed in a hexagon.

Delocalized electrons- electron orbitals overlap to form continuous clouds

Aromatic compounds- include naphthalene (moth balls) and benzaldehyde (flavorings). Benzene provides basis.

Functional groups- have elements besides C and H (most commonly oxygen, nitrogen, sulfur and halogens)

12/1 Introduction to Organic Chemistry

Organic Chemistry- the chemistry of carbon compounds.

- Originally: organic matter formed only by living organisms

- Diamond and graphite are the two allotropes of carbon

Fullerenes- Synthetic forms of carbon

Hydrocarbons- composed of only H and C

- Alkanes

- Alkenes

- Alkynes

- Aromatic Hydrocarbons

- Source of fuel

Buckminster Fuller- 1895-1983- created Fullerene and Geodesic dome shapes

12/2

Alkanes- saturated hydrocarbons. Hydrocarbons are molecules of C and H. Each carbon atom forms 4 chemical bonds. Named by adding –ane to the end of substance

Saturated hydrocarbons- all the C bonds are single and the molecule contains the maximum number of Hydrogen atoms

- Normal alkanes consist of continuous carbon chains. Non- continuous ones have branches

- Tetrahedral carbons- H occupies corners of tetrahedron

- Ethane- free rotation around single- carbon atom

- Isomers- same formula, different organization of atoms

o Isomers are named by Isox, x being the name of the compound

- Alkanes are hydrophobic

o Example: paraffin waxes- mix of straight- chain hydrocarbons from petroleum

o Lotus effect- was on leaves repels water and dirt

Alkenes- hydrocarbons with at least one double bond (share 4 electrons between two atoms)

- Unsaturated with hydrogen

- Add –ene to end to name

- Ethylene ripens tomatoes

Alkynes- hydrocarbons with at least one triple bond (share 6 electrons between two atoms)

- Add –yne to end to name

Acetylene- used in organic synthesis, oxy- acetylene welding and as an illuminant

Cycloalkanes- ring structure with only single bonds

Aromatic compound- based on the benzene ring

A benzene ring is attached to another compound and called phenyl

- straight- chain carbons rotate freely around single bonds

12/5 Functional groups- atom or atoms attached to hydrocarbons

- Alcohols- an H is replaced by hydroxyl (-OH group)

o Named by adding (-ol) to hydrocarbon name

- Ether- general formula RORÌ, an O bonded between Cs

o The R stands for the rest of the carbon chain

- Aldehyde- has a carbonyl group (carbon bonded to O- attached to terminal (end) carbon atom)

- Ketone- has carbonyl group double bonded to an internal (not an end carbon) atom

- Organic acids- acids from organisms (used for metabolism/defense etc). Also called fatty or carboxylic acids

o Has carboxyl functional group (COOH)

7-2 Naming Straight- Chain Hydrocarbons

# Carbons Name

1 Methane

2 Ethane

3 Propane

4 Butane

5 Pentane

6 Hexane

7 Heptane

8 Octane

9 Nonane

10 Decane

- All alkanes end with –ane

- All alkenes end with –ene

- All alkynes end with –yne

For alkenes and alkynes, name with a number in front of the parent chain name to indicate which carbon has the double/triple bond (if there are more than one, include both numbers Ex. 1, 3-pentadiene)

Naming Nonlinear Hydrocarbons

Cyclic alkanes- name by the number of carbons in the largest ring (like straight- chains) but with the prefix cyclo-

- The parent compound is the longest carbon chain

- Give the number of the parent- chain carbon the alkyl group comes off of. When you number the chain, start at the end that is nearest the first change (a change being an alkyl group or multiple bond). The alkyl group is named with the same prefixes as the parent groups (Ex. Methyl, ethyl, propyl, etc.) and the parent compound name (Ex. 3- Methylheptane)

- If there are more than one of the same group, use a prefix (di/tri/etc)

- With alkenes or alkynes, use the longest chain that includes the double/triple bond

- If there is more than one kind of alkyl group, organize them alphabetically

Saturated fat- animal fats, tropical oils, etc. Lead to weight and cholesterol problems

Unsaturated fats- healthier

Models

- Chemical formula

- Structural formula

- Skeletal structure

- Space- fill model

Halides and nitro compound prefixes

F- Fluoro-

Br- Bromo-

CL- Chloro-

I- Iodo-

NO2- Nitro-

- They are still alphebetical

Home