The second reaction, was between ethanol with ethanoic acid, together these make Ethyl Ethanoate. Using 1cm3 of the alcohol, 0.25g of the acid and a few drops of concentrated sulfuric acid to form the ester. The reaction also produced water. Leaving the reaction in a water bath at 80?C. This is left for five minutes to heat up. Water molecules form by using the OH-ions from the alcohol and the H+ ion form the acid. Esters are heated under reflux so the vapours that are lost in condensation can be returned back to the flask therefore helps the volume of desired product to be greater as well as pushing the reaction forward. The ester will then be distilled straight away from the excess reactants and the water. As sulfuric acid was also included, meaning that the reaction took place at a quicker pace, as it is a dehydrating agent- the water molecules will have been expelled. Pouring the contents of the boiling tube into a beaker of cold water, made it easier the smell to be identified. The results showed methyl salicylate had menthol smell. The ethyl ethanoate on the other hand had an acetate type smell , like nail varnish remover.
Addition-elimination reaction mechanism occurred during this reaction, the lone pair on the oxygen atom attacks the sufulric acid and essentially stole a proton, this now gives the oxygen a positive charge. The alcohol molecule carries an oxygen in the hydroxyl group. This contains a lone pair of electrons that will attack the carbon with a slightly positive charge, the oxygen atom will them become positive as it has now bonded with the carbon atom. The proton attached to the oxygen, in this case the hydrogen is then pulled away and attached onto another oxygen in the same molecule by another substance in the solution that is unreacted. The oxygen now has two bonds with two hydrogen ions. This creates a water molecule and will break away from the compound. This means as the carbon-oxygen bond breaks, a now delocalised positive charge is left on the whole molecule. The hydrogen is then removed from this structure by the hydrogen sulphate ion, as the oxygen it was prior removed from has a negative charge.