The oxygen atom in the carboxyl group in benzoic acid is more electronegative due to its lone pair electron. The protons are flying around everywhere. The hydrolysis process would be the following equation: The hydrolysis process must under acidic or basic condition in order to break down the stable ester molecule. The boiling point of the ester was 143° C, only one degree off from the theoretical boiling point of the ester 1,3-dimethylbutyl, 144 ° C. We started with a heptanoic acid, and now we have an ester. Distilled water can extracts the leftover of methanol and small amount of benzoic acid.
And this ester right here, and we'll probably talk more about esters in future videos, this ester right here, just to give you a hint of how to name it, you first start with the group that's attached to this oxygen right here. Let me draw the sulfuric acid a little bit differently. The Fischer esterification method is a fundamental and important synthesis process in training our future chemists in both commercial and academic employment and principles. Benzoic acid is placed into a 250ml beaker and then methanol is added. So you can imagine the next thing that could happen is another oxygen could grab a proton from the medium.
This right here is sulfuric acid, one of the stronger acids. The methanol acts as a nucleophile attacks the benzoic acid. The reason is that oxygen has higher electronegativity compared to carbon. As shown in the diagram below, the esterification is also known as condensation process which water is produced. This guy gave away an electron to this carbonyl carbon. Stage 2: The alcohol nucleophically attacks the carbonyl carbon Figure 5. Actually, let me draw it over here.
The low molecular-weight esters have very pleasant odours and indeed are major components of the flavour and odour aspects of a number of fruits. Anyway, hopefully, you found that useful. You would have your two, three, four, five, six, seven carbons, single bond to an oxygen, and then you have your bond to this oxygen, which is bound to two carbons, one, two carbons, just like that. The name, banana oil, is due to banana odour released by formation of Isopentyl acetate. The actual figure that an ester could be form is 60-70%, which according to the estimation of scientist.
After the ester was isolated a percent yield of 55. So this guy gives an electron to the proton, but the end result is the hydrogen leaves. Another reason for the fluctuation of temperature may be side product formed during reflux is exist in the mixture. And this is what tells you that you are dealing with an ester. To produce methyl benzoate by esterification 2. He can grab a proton from one of these protonated ethanols from the sulfuric acid, or maybe from one of these other intermediate molecules, from anywhere. So, we use distillation to obtain the pure ester from the mixture.
If either one is doubled, the theoretical yield increases to 85%. The low-molecular-weight esters have very pleasant odors and indeed are the major components of the flavor and odor aspects of a number of fruits. The vapors were blocked from escaping the solution by a stream of cold water running up the reflux column. It's already hogging these electrons. And this guy on top is bonded to an oxygen. In general, the oxygen, very electronegative, it's going to be hogging the electrons of this proton, so it can take them away.
So this will result in a ton of these protonated ethanols. Anhydrous sodium sulphate is used to dry the solution and then is filtered out. Let me scratch that out. The low yield is likely caused by an unoptimized workup procedure and suggestions for improving it are given. And maybe I'll make a whole video on sulfuric acid, just to show you all of the resonance structures. So after that happens, what does our newly formed molecule look like? This quantitative error was most likely due to product getting stuck in the apparatus. It had this bond to this hydrogen that it nabbed from the solution, that proton that it nabbed from the solution, and now it has another pair.
So maybe one of the other ethanol molecules, or one of the other intermediaries in this whole reaction. ° Another way to upset the equilibrium is to remove water. So we have this ethanol floating around, and this is one, two carbons. And this tells you what's on the other side of the oxygen in the ester. And notice, it has one, two, three, four, five, six valence electrons. So you could imagine a situation where this proton just jumps off. Actually, I should make it clear.