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ALKANES
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Alkanes area class of HYDROCARBONS
which contain only carbon and hydrogen. Two other terms which
describe alkanes are saturated and paraffins.
SATURATED alkanes means that each carbon is bonded
to four other atoms through single covalent bonds. Hydrogen atoms
usually occupy all available bonding positions after the carbons
have bonded to each other.
PARAFFINS which is derived from a Latin word meaning
"little activity", and means that the compounds are
very unreactive.
The example compounds of ethane and pentane are shown on the
LEFT.
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| Alkanes are the principle compounds found fossil fuels such as natural
gas and oil, which is further refined
into gasoline. These compounds
thus provide a large share of the energy and are also the raw
materials for much of the synthetic compounds of various materials,
fibers, drugs, plastic, and many other compounds used in modern
society. |
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Properties |
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Structure |
Physical Properties |
Chemical Reactivity |
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CnH2n+2
Example: CH3CH3
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Boiling points depend
on chain length.
Non polar
Insoluble in water
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No functional groups, saturated, and class name of
paraffins which means - Unreactive to other chemicals.
All compounds: Combustion
Reaction
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ROOT ALKANE NAMES
Root names give the number of carbons in the longest continuous
chain. Root names are used with various "endings" to
indicate branches, type of bonds between carbons, and functional
groups.
The following list gives the most basic root the with normal
hydrocarbon alkane endings for the number of carbons in the longest
continuous chain. Memorize this list.
Example: root = "eth" + alkane ending = "ane"
= ethane
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No. of
Carbons |
Root Name |
Formula
CnH2n+2 |
Structure |
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1 |
methane |
CH4 |
CH4 |
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2 |
ethane |
C2H6 |
CH3CH3 |
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3 |
propane |
C3H8 |
CH3CH2CH3 |
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4 |
butane |
C4H10 |
CH3CH2CH2CH3 |
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5 |
pentane |
C5H12 |
CH3CH2CH2CH2CH3 |
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6 |
hexane |
C6H14 |
CH3CH2CH2CH2CH2CH3 |
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7 |
heptane |
C7H16 |
CH3CH2CH2CH2CH2CH2CH3 |
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8 |
octane |
C8H18 |
CH3CH2CH2CH2CH2CH2CH2CH3 |
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9 |
nonane |
C9H20 |
CH3CH2CH2CH2CH2CH2CH2CH2CH3 |
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10 |
decane |
C10H22 |
CH3CH2CH2CH2CH2CH2CH2CH2CH2CH3 |
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