To peter blessing:
esterification reaction 
R-OH(alkanol) + R'-C^=O-OH(alkanoic acid) ~ R-C^O-OR'[ethyl ethanoate(ester)] +H2O under the presence of conc. H2SO4 which acts as the catalyst.

<h2>Isomers</h2>
<p>It is possible for two organic <a data-lesson="compounds-2" data-subject="chemistry" data-tutorial="quantitative-aspects-chemical-change" href="https://app.ulearngo.com/chemistry/quantitative-aspects-chemical-change/compounds-2">compounds</a> to have the same <em>molecular formula</em> but a different <em>structural formula</em>. Look at the two <a data-lesson="what-are-organic-molecules" data-subject="chemistry" data-tutorial="organic-molecules" href="https://app.ulearngo.com/chemistry/organic-molecules/what-are-organic-molecules">organic compounds</a> that are shown in the figure below for example.</p>
<div class="wp-caption alignnone" style="width: 666px"><img alt="8808734285e1dd73b3a8263c4873ebe9.png" height="234" src="https://data.ulearngo.com/assets/9d164b9f-0ac8-41af-af5b-22d549f961e2" width="666"/><p class="wp-caption-text">Isomers of a 4-carbon organic compound with the molecular formula \(\text{C}_{4}\text{H}_{10}\). (a) butane and (b) 2-methylpropane.</p></div>
<div class="ns-school-defn2">
<h4>Fact:</h4>
<p>Both butane and 2-methylpropane (isobutane) are used in camping stoves and lighters.</p>
<img alt="" src="https://data.ulearngo.com/assets/44e5590b-24c2-490a-ac59-da3770b45a27"/></div>
<p>If you were to count the <a data-lesson="atomic-and-atomic-mass-number" data-subject="chemistry" data-tutorial="chemistry-essential-ideas" href="https://app.ulearngo.com/chemistry/chemistry-essential-ideas/atomic-and-atomic-mass-number">number</a> of carbon and hydrogen <a data-lesson="chemical-formulas" data-subject="chemistry" data-tutorial="atoms-molecules-ions" href="https://app.ulearngo.com/chemistry/atoms-molecules-ions/chemical-formulas">atoms</a> in each compound, you would find that they are the same. They both have the same molecular formula \(\text{C}_{4}\text{H}_{10}\), but their structure is different and so are their properties. Such compounds are called <strong>isomers</strong>.</p>
<div class="ns-school-emp">
<h3>Definition: Isomer</h3>
<div class="ns-school-defn">
<p>In chemistry, isomers are molecules with the same molecular formula but different structural formula.</p>
</div>
</div>
<p>Isomers are molecules with the same molecular formula and often (though not always) with the same kinds of chemical bonds between atoms, but with the atoms arranged differently.</p>
<p>The isomers shown above differ only in the location of the carbon atoms. The functional groups are the same but butane has all four carbons in one chain, while 2-methylpropane has three carbons in the longest chain and a methyl group attached to the second carbon in the chain. It is also possible to have <em>positional</em> isomers (see figure below). In this case the \(-\text{OH}\) functional group can be on different carbon atoms, for example carbon 1 for pentan-1-ol, on carbon 2 for pentan-2-ol or on carbon 3 for pentan-3-ol.</p>
<div class="wp-caption alignnone" style="width: 831px"><img alt="02aa28e1874ff4f775d81f55dc5f822f.png" height="488" src="https://data.ulearngo.com/assets/a2799bc4-fe64-4fb0-97b3-22e6f7780811" width="831"/><p class="wp-caption-text">The structural and condensed structural representations of the isomers (a) pentan-1-ol, (b) pentan-2-ol and (c) pentan-3-ol.</p></div>
<p>Positional isomers are also found in esters. If one <a data-lesson="production-of-esters" data-subject="chemistry" data-tutorial="organic-molecules" href="https://app.ulearngo.com/chemistry/organic-molecules/production-of-esters">ester</a> was made from ethanol and hexanoic acid and another was made from hexanol and ethanoic acid the two esters produced are isomers (see figure below).</p>
<p><img alt="879666bc19b579906a007827e8323137.png" src="https://data.ulearngo.com/assets/abf59555-e17b-47fb-9c93-903bb024505e"/></p>
<div class="wp-caption alignnone" style="width: 618px"><img alt="c8de70d05eea4f554fa1f1af52a8f879.png" height="146" src="https://data.ulearngo.com/assets/13c79a6e-5a87-4147-bdba-8cde05174b87" width="618"/><p class="wp-caption-text">The structural representations of the isomers (a) ethyl hexanoate and (b) hexyl ethanoate.<span style="font-size: 16px;"> </span></p></div>
<p>It is important to note that molecules need not have the same functional groups to be isomers. For example propanone (commonly known as acetone) and propanal (see figure above) have the same molecular formula (\(\text{C}_{3}\text{H}_{6}\text{O}\)) but different functional groups and properties (see table below). These types of isomers are <strong>functional isomers</strong>.</p>
<div class="wp-caption alignnone" style="width: 624px"><img alt="2aa86675327ca40c128272be8d7659c4.png" height="146" src="https://data.ulearngo.com/assets/c6621f0c-e1a8-4044-8561-b29a35e510a8" width="624"/><p class="wp-caption-text">Two \(\text{C}_{3}\text{H}_{6}\text{O}\) isomers (a) propanone and (b) propanal.<span style="font-size: 16px;"> </span></p></div>
<div>
<table summary="      ">
<tbody>
<tr>
<td>
<p><strong>Name</strong></p>
</td>
<td>
<p><strong>Functional Group</strong></p>
</td>
<td>
<p><strong>Melting point (℃)</strong></p>
</td>
<td>
<p><strong>Boiling point (℃)</strong></p>
</td>
<td>
<p><strong>Reactivity</strong></p>
</td>
</tr>
<tr>
<td>
<p>propan<em>one</em></p>
</td>
<td>
<p>ketone</p>
</td>
<td>
<p>\(-\text{95}\)</p>
</td>
<td>
<p>\(\text{56}\)</p>
</td>
<td>
<p>less reactive</p>
</td>
</tr>
<tr>
<td>
<p>propan<em>al</em></p>
</td>
<td>
<p>aldehyde</p>
</td>
<td>
<p>\(-\text{81}\)</p>
</td>
<td>
<p>\(\text{48}\)</p>
</td>
<td>
<p>more reactive</p>
</td>
</tr>
</tbody>
</table>
<div>
<p><em>Table: Some properties of the isomers propanone and propanal.</em></p>
</div>
</div>
<p>Heptanoic acid and butyl propanoate (see figure below) are another example of <em>functional</em> isomers (containing different functional groups). They both have the same molecular formula of \(\text{C}_{7}\text{H}_{14}\text{O}_{2}\) but have different functional groups and different properties (see table below).</p>
<div class="wp-caption alignnone" style="width: 624px"><img alt="d3deb99d49b804ba565472273da9f7aa.png" height="323" src="https://data.ulearngo.com/assets/688aeb3b-836e-4a30-b343-9521c64e55f5" width="624"/><p class="wp-caption-text">The structural representations of the isomers (a) heptanoic acid and (b) butyl propanoate.<span style="font-size: 16px;"> </span></p></div>
<div>
<table summary="      ">
<tbody>
<tr>
<td>
<p><strong>Name</strong></p>
</td>
<td>
<p><strong>Functional group</strong></p>
</td>
<td>
<p><strong>Melting point (℃)</strong></p>
</td>
<td>
<p><strong>Boiling point (℃)</strong></p>
</td>
</tr>
<tr>
<td>
<p>heptanoic acid</p>
</td>
<td>
<p>carboxylic acid</p>
</td>
<td>
<p>\(-\text{7.5}\)</p>
</td>
<td>
<p>\(\text{223}\)</p>
</td>
</tr>
<tr>
<td>
<p>butyl propanoate</p>
</td>
<td>
<p>ester</p>
</td>
<td>
<p>\(-\text{89.5}\)</p>
</td>
<td>
<p>\(\text{145}\)</p>
</td>
</tr>
</tbody>
</table>
<div>
<p><em>Table: The different <a data-lesson="physical-chemical-properties" data-subject="chemistry" data-tutorial="chemistry-essential-ideas" href="https://app.ulearngo.com/chemistry/chemistry-essential-ideas/physical-chemical-properties">physical</a> properties of the isomers heptanoic acid and butyl propanoate.</em></p>
</div>
</div>
<section>
<div class="ns-school-defn2">
<div class="ns-school-defn2">
<div>
<div> </div>
</div>
</div>
</div>
</section>

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Isomers

Chemistry generally explores the substances of which matter is composed, the investigation of their properties and reactions, and the use of such reactions to form new substances. 

Chemistry

Learn about the special properties of carbon, functional groups, isomers, IUPAC naming, physical properties, and reactions of organic molecules, as well as the formation and impact of polymers in this tutorial.


Isomers

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