Extraction with Acid and Alkaline
Title:Extraction:Extraction with acid and alkaline
Objective:
1. To recover benzoic acid and p-dichlorobenzene from its mixture using acid-alkaline extraction. 2. To determine the percentage recovery and melting point of benzoic acid and p-diclorobenzene.
Apparatus:Separatory funnel(250mL),Buchner funnel,beaker.
Materials:Benzoic acid,p-dichlorobenzene,ether,10% NaOH,conc.HCl,distilled water, anhydrous CaCl2.
Introduction:
Organic compounds in an aqueous mixture can be separated by shaking the aqueous solution with a solvent which is immiscible with water. Extraction involves dissolving either a compound or compounds from solid into a solvent or from solution into another solvent. Acid-alkaline extraction is a commonly used method to recover a compound from solid or liquid and also a form of solvent-solvent extraction. Acid-alkaline extraction is a method to separate compounds according to their relative solubility in two different immiscible solutions. Usually, acid-alkaline extraction is being used to recover a compound from solid or liquid. The two solvents used to conduct acid-alkaline extraction must be insoluble to one another. Therefore, the mixture of two solvents will be separated into two layers. The less dense solvent will be at upper layer while the denser solvent will stay at lower layer. In most experiment,one of the solvent used will be water on an aqueous solution and the other will be organic solvent that is insoluble in water.The organic solvent used have to be volatile because it can be easily removed by evaporation when forming crystals. Phenolic compounds will undergo salt formation with sodium hydroxide solution, NaOH.Therefore,sodium hydroxide solution is allow to use to extract a carboxylic acid or phenolic compound from its solution in an organic solvent.An organic solvent can be used to remove organic impurities from a carboxylic acid or phenol dissolved in aqueous sodium hydroxide.Aqueous solution of Sodium
Objective:
1. To recover benzoic acid and p-dichlorobenzene from its mixture using acid-alkaline extraction. 2. To determine the percentage recovery and melting point of benzoic acid and p-diclorobenzene.
Apparatus:Separatory funnel(250mL),Buchner funnel,beaker.
Materials:Benzoic acid,p-dichlorobenzene,ether,10% NaOH,conc.HCl,distilled water, anhydrous CaCl2.
Introduction:
Organic compounds in an aqueous mixture can be separated by shaking the aqueous solution with a solvent which is immiscible with water. Extraction involves dissolving either a compound or compounds from solid into a solvent or from solution into another solvent. Acid-alkaline extraction is a commonly used method to recover a compound from solid or liquid and also a form of solvent-solvent extraction. Acid-alkaline extraction is a method to separate compounds according to their relative solubility in two different immiscible solutions. Usually, acid-alkaline extraction is being used to recover a compound from solid or liquid. The two solvents used to conduct acid-alkaline extraction must be insoluble to one another. Therefore, the mixture of two solvents will be separated into two layers. The less dense solvent will be at upper layer while the denser solvent will stay at lower layer. In most experiment,one of the solvent used will be water on an aqueous solution and the other will be organic solvent that is insoluble in water.The organic solvent used have to be volatile because it can be easily removed by evaporation when forming crystals. Phenolic compounds will undergo salt formation with sodium hydroxide solution, NaOH.Therefore,sodium hydroxide solution is allow to use to extract a carboxylic acid or phenolic compound from its solution in an organic solvent.An organic solvent can be used to remove organic impurities from a carboxylic acid or phenol dissolved in aqueous sodium hydroxide.Aqueous solution of Sodium
References: 1. P-dichlorobenzene.Retrieved at 5/2/2013 from http://www.chemicalland21.com/industrialchem/organic/P-DICHLOROBENZENE.htm 2. Benzoic acid.Retrieved at 5/2/2013 from http://global.britannica.com/EBchecked/topic/61357/benzoic-acid 3. Sodium benzoate.Retrieved at 4/2/2013 from http://pubchem.ncbi.nlm.nih.gov/summary/summary.cgi?cid=517055 4. Carboxylic acids.Retrieved at 3/2/2013 from http://www.chemguide.co.uk/organicprops/acids/background.html