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Solubility Essay

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Solubility is the property of a solid, liquid or gaseous chemical solute to dissolve in a solid, liquid or gaseous solvent to form a solution [1]. The solubility of a particular substance is dependent on the physical and chemical properties of both the solute and solvent [1]. The temperature, pressure and pH of the solution also has an effect on the solubility. The extent of the solubility of a certain solute in a particular solvent is measured as saturation, where adding more solute will not increase the concentration of the solution and will precipitate the excess in the solution.
Phase transfer reagents are used to facilitate movement of a reactant from one phase to another [2]. For example, from the aqueous phase to the organic phase.
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The two compounds that showed benzoic acid as soluble was acetone and ethanol and benzoic acid did not appear to be soluble in hexanes or water. Acetone dissolved the benzoic acid at both room temperature and increased temperature, while benzoic acid in ethanol was only slightly soluble at room temperature and completely soluble at increased temperature. Acetone is a ketone, which is a carbon chain with an oxygen attached to it [1]. Ethanol is an alcohol; it is an ethyl group with a hydroxyl group attached to it [1]. Water is a covalent compound and hexanes is an alkane with a mixture of isomers of carbon-6. When comparing the functional groups and structures of the different solvents, the ethanol and acetone contain non-polar carbon chains with polar branches, while water is a completely polar molecule and hexanes contains no dipole moments. The non-polar carbon chains of the acetone and ethanol interact with the aromatic ring of the benzoic acid and dissolve the compound. The benzoic acid dissolved in acetone easier because the polar atom is in the center of the carbon chain rather than the side. The ethanol required heating because the increased kinetic energy of the solvent molecules broke apart the bonds of the solute easier. Ethanol would be the best for recrystallizing benzoic acid because you want a solvent in which the solute is insoluble at room temperature and soluble at high temperatures. The benzoic acid can be dissolved at high temperatures and slowly precipitated out to leave impurities in the solvent, resulting in pure benzoic
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