Compounds in which each member differs from the one before it by the same additional unit are called a homologous series. Ex: methane, ethane, propane, etc. Ex. What is the molecular formula for the alkane that has 8 carbon atoms? alkane formula: C n H 2n+2 n = 8: C n H 2n+2 = C 8 H 28+2 = C 8 H 18 Sketch its structural formula: Ball and stick view: Skeletal view: Note how the actual shaped is bent or kinked.
Use the table shown to name them. Each alkane is named by adding the prefix to –ane. Ex. What is the name of the alkane of the last example? Ex. What is the name of the alkane that has five C atoms? What is its molecular formula? Sketch its structural formula. octane pentane C 5 H 12
B. The alkenes are a homologous series of unsaturated (not all single bonds) hydrocarbons that contain one double bond. There must be at least 2 carbon atoms to form an alkene. The simplest member is ethene (also known as ethylene and olefin). ethene: structural formula: Other views: C2H4C2H4
Ethene is the chemical that causes fruits to ripen. They produce it naturally or it can be artificially applied.
Many geologists and scholars believe that the famous Greek Oracle at Delphi went into her trance-like state as an effect of ethylene rising from ground faults.
Next alkene after ethene: ___________ Other views: molecular formula: structural formula: C3H6C3H6 propene How many carbon atoms does it have? How many double bonds? 3 1
The next alkenes are: butene, pentene, etc. Alkenes are named using the same prefixes that are used for alkanes. The general formula for alkenes is: C n H 2n Ex. What are the name and general formula for the alkene that has nine carbon atoms? C 9 H 18 nonene
C. The alkynes are a homologous series of unsaturated (not all single bonds) hydrocarbons that contain one triple bond. As with the alkenes, there must be at least 2 carbon atoms to form an alkyne. The simplest member is ethyne (also known as acetylene): molecular formula: structural formula: Other views: C2H2C2H2
Ethene = acetylene Combustion of acetylene with oxygen produces a flame of over 3600 K (3300 °C, 6000 °F), Oxyacetylene is the hottest burning common fuel gas
Demonstration: CaC 2 + 2H 2 O → Ca(OH) 2 + C 2 H 2 Carbide lamps:
In carbon-14 dating, the object to be dated has carbon C. It is allowed to come into contact with lithium metal to form lithium carbide. LiC 2 + 2H 2 O → 2CaOH + C 2 H 2
Next alkyne after ethyne: Other views: molecular formula: structural formula: C3H4C3H4 propyne How many C atoms does it have? How many triple bonds? 3 1
The next alkynes are: butyne, pentyne, etc. Alkynes are named using the same prefixes that are used for alkanes and alkenes. The general formula for alkynes is: C n H 2n-2 Ex. What are the name and general formula for the alkyne that has seven carbon atoms? heptyne misprint!!!
Ex. Name and give the molecular formula of the… …alkane with 6 carbon atoms: …alkene with 10 carbon atoms: …alkyne with 7 carbon atoms: hexane decene heptyne In sum: C 6 H 14 C 10 H 20 C 7 H 12
D. The examples so far are _______ hydrocarbons. Other types include ________ hydrocarbons. Two examples of these are shown here: _______ hexane A _________ “ring” structuralskeletal structuralskeletal Hydrocarbons with __________ single & double bonds are called _______. Benzine itself is a colorless, highly flammable liquid found in _______. It is ____________. It is used to make solvents, dyes, and ____________. cyclo benzene open cyclic alternating aromatics crude oil carcinogenic polymers
Steroids – 3 cyclohexanes and 1 cyclopentane fused together Examples: Cholesterol the sex hormones estradiolestradiol and testosterone, and thetestosterone anti-inflammatoryanti-inflammatory drug dexamethasonedexamethasone, as well as hundreds of others found in plants, animals and fungi. They differ from each other by the functional groups attached to this four ring core and by the oxidation stateoxidation state of the rings.
What is this ring of hydrocarbons, which is produced in volcanoes, forest fires and cigarette smoke…? Very useful, very toxic.