Differences Of Benzoic Acid From The Toluene-Benzoic Acid Mixture

721 Words 3 Pages
Aims of Experiment
1. To extract benzoic acid from the toluene-benzoic acid mixture, using oxidation-reduction reaction (chemical properties) and difference of solubility (physical properties) –Expt. 1
2. To learn how to recrystallize the solid organic compounds well for getting more purified compounds –Expt. 2
3. To find which differences between raw product and recrystallized product are observed. –Expt. 2
4. To determine melting point range of organic compounds with digital melting point apparatus, splitting into some parts in terms of raw benzoic acid product, purified product benzoic acid standard and the mixture of them. –Expt. 2
5. To determine the percentage of raw benzoic acid from the toluene-benzoic acid mixture and recrystallized
…show more content…
When toluene (C7H8), which is a colorless, water-insoluble, and flammable liquid, is oxidized, it loses two hydrogen atoms and becomes the benzoic acid. However, other than using oxidation process, there is another way to obtain benzoic acid, called liquid-liquid extraction. By adding an aqueous solution of sodium hydroxide (Base), benzoic acid is converted to the sodium salt of benzoic acid (conjugate base), which makes it have a much higher solubility in water. However, toluene has water-insoluble property, which means that the separation between toluene and benzoic acid can occur with the difference of solubility in …show more content…
The fundamental principle of recrystallization is to use the difference of solubility according to the temperature, which makes some impurities remain in solution in order to get higher purity. Because of its reason, depending on several factors such as the volume of solvent, the speed of recrystallization, the shape or structure, size, and purity can be changed. And this is the reason why doing recrystallization is the most important in the Organic

Related Documents