The reaction the occurred in the experiment was a reaction between acetic acid and isopentyl alcohol to form isopentyl acetate and water. The esterification of acetic acid with isopentyl alcohol occurs in four steps. The first step in the reaction mechanism is the protonation of acetic acid with a proton from the concentrated sulfuric acid that was added to the reaction mixture. In the second step, acetic acid reacts with the isopentyl alcohol to form a reaction intermediate which undergoes proton transfer or rearrangement protonation. Water acts as a leaving group in the third step and is removed from the reaction intermediate.
Observations Step Observation Adding sulfuric acid into the alcohol and carboxylic acid solution Surface of the round bottom flask is warm Poring the ester solution in the bottle after reflux Dense gas can be seen Washing the ester with distilled water The ester layer is immiscible with distilled water. Washing the ester with sodium carbonate solution Effervescence -bubbles of gas produced -a ‘pop’ sound could be heard when the separating funnel is closed and opened again. The ester layer is immiscible with the sodium carbonate solution Adding anhydrous calcium chloride into the ester solution Heat would be produced as the surface of the conical flask feels warm. Anhydrous calcium chloride crystals would clump up after swirling.
In the experiment, sulfuric acid acted as a catalyst and necessary for this reaction to occur. There was a change between the –OH group of carboxylic acid to an –OCH2CH3 group in the reaction. It was a result of nucleophilic substitution
3. To purify and identify the product, recrystallization is used in order to purify the product, then melting point and TLC techniques are used to identify the product. Theory 4. In nucleophilic substitution reactions, there are two possibilities, either Sn1 or Sn2. In this particular experiment, an Sn2 reaction
Abstract In this laboratory, methanol is reacted with a tertiary alkyl chloride to make ether. The triphenylmethyl is isolated from the triphenylmethyl chloride. Methanol is then added and the class does the recrystallization . The methanol acts as a solvent for the reaction as a nucleophile. Because it is a tertiary benzylic halide, the reaction is considered an SN1 type.
Acetic acid (CH3COOH) and formaldehyde (HCHO) can be obtained by processing methanol and is also used for petrol bending (petroleum derived liquid). A large proportion of methanol is used to make motor spirit, vinyl acetate, acetic anhydride these chemicals is used for the manufacture of adhesives, coating, photographic film, synthetic fiber, synthetic rubber and thermoplastic and mainly the methyl-tertiary butyl ether (MTBE) which reduces “knock” and also the proportion of CO and hydrocarbon in the exhaust. we can produce various aromatic hydrocarbons and alkanes suitable for petrol (hydro carbon with five to eight carbon atoms ) by throwing the stream of vapour over alumina at temp. around 600 kelvin. An equilibrium mixture of methanol, dimethyl ether and water is produced which has 25 percent methanol.
Ethyl formate was the fasted to react because the pH stabilized the fastest. This may have been because the carbonyl was less sterically hindered being that it was only connected to a hydrogen allowing the nucleophile to attack the fastest. The electronic factor for ethyl formate was neutral in being electron withdrawing or electron donating, but more electron withdrawing meaning the carbonyl was more reactive. Ethyl acetate was the second ester that reacted the fasted after ethyl formate. This could have been because it was more sterically hinder since the carbonyl group was connected to a primary carbon.
It seems that solvents play a pivotal role in the liquid phase catalytic reaction. The conversion of benzyl alcohol is 5% under solvent-free conditions (Table 1, entry 1). The conversion percentage of benzyl alcohol are different in nonpolar to polar solvents. As demonstrated by Table 1, the conversion of benzyl alcohol is 40%, 62%, 93% and 10% when n-hexane, toluene, acetonitrile and H2O are used as solvent, respectively (Table 1, entries 2-5). This indicates that aprotic acetonitrile with large dielectric constant promote the collisions and dispersion of oxygen source, the alcohol and the catalyst [15].
The superficial velocity of reactant gas inserted into the reactor is very fast by the range of 0.4 to 0.7 m/s and it only taken few seconds of contact time from 5 to 20s in the reactor. Ratio for the gas feed into the fluidized bed reactor by the composition of C3H6: NH3: O2 is 1: 1-1.2: 10-12. The reactor are fed with slightly excess of ammonia of stoichiometry proportion to get the reaction closer to completion and fastening the process of catalyst regeneration. Ammoxidation of propylene give higher conversion till 98% and the selectivity above than 80%. Byproduct produces from this reaction by weight percentage (% wt) base on acrylonitrile are acetonitrile 2-4 % and hydrogen cyanide 14 to 18 %.
According to Farkade & Pathre (2012), the presence of oxygen gives you more desirable combustion resulting into low emission of CO, HC and higher emission of CO2 as a result of complete combustion. With this, while butanol contains 22% oxygen, ethanol has higher percentage with 36% oxygen. Octane number as the third property indicates the capacity of the fuel to ignite. The higher the rating, ignition is unlikely to occur. Pure ethanol has an octane number of 112.5 to 114 which is more or less 77% than the pure butanol’s.