Ethyl acetate from acetic acid and alcohol

Ethyl benzoate is prepared in a similar way, by boiling benzoic acid (30 g.) in 100 c.c. of absolute alcohol for four hours under reflux condenser with 3 c.c. of concentrated sulphuric acid. Most of the alcohol is then removed by distillation, 300 c.c. of water are added, 

The formation of an ester from acid and alcohol corresponds in a formal way to salt formation from acid and metallic hydroxide. 

As far as the velocity and the extent of the conversion are concerned, the two processes are, however, altogether different. Whereas an acid is practically instantaneously and completely converted into a salt by an equivalent amount of a sufficiently strong base (neutralisation), a process on which, indeed, alkalimetry and acidimetry depend, it is not possible to obtain from equimolecular amounts of acid and alcohol the theoretical (calculated) amount of ester. A certain maximal quantity of ester is formed, but always falls short of the theoretical, and it is impossible, even by indefinitely extending the duration of the reaction, to make the unchanged acid and alcohol produce ester in excess of that maximum. If, for example, equimolecular amounts of acetic acid and alcohol are allowed to interact in a closed system, only two-thirds of each enter into reaction, and it is impossible to induce the remaining third of acetic acid to react with that of alcohol. The maximum yield of ester therefore amounts to only two-thirds, or 66-7 per cent, of the theoretical quantity. The quantitative difference in the course of the two reactions mentioned above depends on the fact that esterification is a so-called reversible reaction , i.e. one in which the reaction products represented on the right-hand side of the equation (ester and water) also interact in the opposite direction  

Strictly speaking, all chemical reactions are reversible, but when the extent of the reverse reaction is immeasurably small and, consequently, the transformation as a whole proceeds practically in one direction only, the reversibility is neglected. The synthesis of water from its elements is a reaction of this kind. But we should nevertheless bear in mind that already at +2000° the opposite reaction (decomposition) takes place to such an extent that we must use the equation  

The conditions of the reaction are thus controlled by the temperature, and indeed in such a way that endothermic reactions (i.e. those which involve the absorption of energy) are, in general, favoured by a rise of 

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