lecture 2 - Structure Alkanes and Cycloalkanes Chapter 2...

Info iconThis preview shows pages 1–4. Sign up to view the full content.

View Full Document Right Arrow Icon
1 Alkanes Alkanes and and Cycloalkanes Cycloalkanes Chapter 2 Chapter 2 Structure Structure ± Hydrocarbon: a compound composed only of carbon and hydrogen ± Saturated hydrocarbon: a hydrocarbon containing only single bonds Structure ± Alkane: Alkane: a saturated hydrocarbon whose carbons are arranged in an open chain ± Aliphatic hydrocarbon: Aliphatic hydrocarbon: another name for an alkane Structure Structure ± Shape tetrahedral about carbon all bond angles are approximately 109.5° Memorize this Table Memorize this Table Drawing Alkanes Drawing Alkanes ± Line-angle formulas an abbreviated way to draw structural formulas each vertex and line ending represents a carbon CH 3 2 2 3 3 2 3 3 2 2 2 3 Pentane Butane Propane Structural formula Ball-and- stick model Line-angle formula
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
2 Constitutional Isomerism Constitutional Isomerism ± Constitutional isomers: Constitutional isomers: compounds with the same molecular formula but a different connectivity of their atoms example: C 4 H 10 CH 3 2 2 3 Butane (bp -0.5°C) 3 3 CHCH 3 2-Methylpropane (bp -11.6°C) Constitutional Isomerism Constitutional Isomerism do these formulas represent constitutional isomers? find the longest carbon chain 3 2 3 3 3 3 2 CHCHCH 3 3 3 and (each is C 7 H 16 ) Constitutional Isomerism number each chain from the end nearest the first branch compare chain lengths as well as the identity and location of branches 3 2 3 3 3 3 2 3 3 3 4 4 5 4 3 1 and 5 1 1 2 2 3 3 5 2 5 4 3 21 Constitutional Isomerism Constitutional Isomerism World population World population is about is about 6,000,000,000 6,000,000,000 4,111,846,763 4,347 75 3 1 Constitutional Isomers Molecular Formula CH 4 C 5 H 12 C 10 H 22 C 15 H 32 C 30 H 62 36,797,588 C 25 H 52 Are these Constitutional Isomers? Are these Constitutional Isomers? Nomenclature of Alkanes Alkanes
Background image of page 2
3 Nomenclature Nomenclature - IUPAC IUPAC Prefix tells the number of carbon atoms undec- dodec- tetradec- pentadec- hexadec- heptadec- nonadec- eicos- tridec- 11 12 13 14 15 16 17 octadec- 18 19 20 Prefix meth- eth- prop- but- pent- hex- oct- non- dec- 1 2 3 4 5 6 7 hept- 8 9 10 Carbons Carbons Prefix Nomenclature Nomenclature - IUPAC IUPAC ± Parent name: the longest carbon chain ± Substituent: a group bonded to the parent chain alkyl group : a substituent derived by removal of a hydrogen from an alkane; given the symbol R- Alkane Alkyl group CH 4 Name Name Methane CH 3 - Methyl group CH 3 CH 3 Ethane CH 3 CH 2 - Ethyl group Nomenclature - IUPAC IUPAC 1.The name of a saturated hydrocarbon with an unbranched chain consists of a prefix and suffix 2. The parent chain is the longest chain of carbon atoms 3. Each substituent is given a name and a number CH 3 CH CH 3 3 2-Methylpropane 1 2 3 Nomenclature Nomenclature - IUPAC IUPAC 4. If there is one substituent, number the chain from the end that gives it the lower number 3 2 2 CHCH 3 3 2-Methylpentane 1 2 3 4 5 5 4 3 2 1 (not 4-methylpentane) Nomenclature - IUPAC IUPAC ± Alkyl groups 1-methylethyl (isopropyl) propyl ethyl methyl Condensed Structural Formula Name CH 3 -CH 2 CH 3 3 2 CH 2 CH 3 -CHCH 3
Background image of page 3

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Image of page 4
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 09/06/2009 for the course CHEM chem 12 AB taught by Professor Valentin during the Spring '09 term at Evergreen Valley.

Page1 / 17

lecture 2 - Structure Alkanes and Cycloalkanes Chapter 2...

This preview shows document pages 1 - 4. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online