Editing Butanol (section)

==Isomers==
The unmodified term ''butanol'' usually refers to the [[open-chain compound|straight chain]] isomer with the alcohol [[functional group]] at the terminal carbon, which is also known as [[1-butanol]].  The straight chain isomer with the alcohol at an internal carbon is ''sec''-butyl alcohol or [[2-butanol]].  The branched isomer with the alcohol at a terminal carbon is [[isobutanol]] or 2-methyl-1-propanol, and the branched isomer with the alcohol at the internal carbon is [[Tert-Butyl alcohol|''tert''-butyl alcohol]] or 2-methyl-2-propanol.

{|class="wikitable skin-invert-image"
|-
|[[Image:1-Butanol skeletal.svg|138px]]
|[[Image:2-butanol Line-Structure.svg|93px]]
|[[Image:Isobutanol.svg|113px]]
|[[Image:Tert-butyl-alcohol-2D-skeletal.svg|100px]]
|-
|[[1-Butanol]] (''n''-butanol)
|[[2-Butanol]] (''sec''-butyl alcohol)
|[[Isobutanol]] (2-methylpropan-1-ol)
|[[Tert-Butyl alcohol|''tert''-butyl alcohol]] (2-methylpropan-2-ol)
|}

The butanol isomers have different melting and boiling points.  1-Butanol and isobutanol have limited solubility, ''sec''-butyl alcohol has substantially greater solubility, whereas ''tert''-butyl alcohol is [[miscible]] with water.  The hydroxyl group makes the molecule polar, promoting solubility in water, while the longer hydrocarbon chain mitigates the polarity and reduces solubility.