Chapter 25 Section 1
Organic Chemistry
-study of compounds containing carbon
hydrocarbons- organic compounds that only
contain C and H
*remember each carbon forms four bonds
simple formula- shows the # and types of atoms
structural formula- shows the #, type and
arrangement of atoms
molecular formula- shows the shapes of
molecules
ex- C4H10
-can also write condensed structural formula a
different way
CH3(CH2)2CH3
Alkanes (end with –ane, simplest hydrocarbons, contain
only single covalent bonds)
# of C
Prefix
Simple Formula
1
methCH4
2
ethC2H6
3
propC3H8
4
butC4H10
5
pentC5H12
6
hexC6H14
7
heptC7H16
8
octC8H18
9
nonC9H20
10
decC10H22
-all alkanes that are straight chains are named
n-alkane (means normal)
-look back at C4H10 example= n-butane
Branched Chain Alkanes
-alkane group takes the place of a hydrogen atom
-called a substituent
alkyl group- hydrocarbon substituent
-ends with –yl (take away -ane)
-carbon contains one less H
-look at # of C to name
ex- CH3 = methyl
C2H5 = ethyl
Naming Branched Chain Alkanes
1) Find the longest chain = parent molecule
ex- heptane
2) # the C’s in the chain, making sure alkyl
groups have lower numbers, can count
backwards
ex- 2,3,4 instead of 4,5,6
3) Add #’s to names of alkyl groups, with a dash
in between
ex- 2-methyl
3-methyl 4-ethyl
4) Use prefixes to denote multiples of the same
alkyl groups, commas between #’s
ex- 2,3-dimethyl
5) Put alkyl groups in alphabetical order
ignoring prefixes
ex- 4-ethyl-2,3-dimethyl
6) **Use proper punctuation
-commas separate #’s
-hyphens separate #’s and letters
-no spaces
7) Add parent chain name
ex- 4-ethyl-2,3-dimethylheptane
*Remember prefixes*
2 = di3 = tri4 = tetra5 = penta6 = hexa7 = hepta8 = octa9 = nona10 = deca-
Drawing Structural Formula From Name
1) Find parent chain and draw
2) # C’s on parent chain
3) Identify substituents and attach to proper C
4) Add hydrogen as needed
Try These!!
1) 3-ethylhexane
2) 2,2,4-trimethylpentane
3) 3-ethyl-3,4-dimethyloctane