Chirality – Isolation of Limonene from Citrus Fruits Introduction: Terpenes are a large and varied class of hydrocarbons produced by a wide variety of plants. Many essential oils belong to the terpene class. They are made up of two or more five carbon units that are called isoprenes. Limonene is a terpene that can be separated from orange peels almost 100% in the (R)-(+)-limonene form. Other citrus fruits like lemons, grapefruits, limes, and tangerines contain the compound as well. The purity of the oil extracted from the oranges can be determined by physical properties such as optical rotation and refractive index. In this experiment, limonene will be isolated by steam distillation. Normally, big molecules such as limonene
…show more content…
The isolated limonene left over was dissolved in 3 mL of ethanol. The solution was then shaken to get rid of the cloudiness and get a clear solution. Using a Pasteur pipette, the solution was transferred to a 10 mL volumetric flask. The Erlenmeyer flask was rinsed several times with 1 mL portions of ethanol and transferred to the volumetric flask. The flask was filled up to the calibration mark, with ethanol. The flask was inverted several times to mix the solution thoroughly. The solution was handed over to a TA to measure the observed rotation and the observed rotation was recorded.
Table of Chemicals: Formula: C10H16 Molar Mass:136.24 g/mol Melting Point: -74oC Boiling Point: 175-177oC Density: 0.844 g/mL Refractive Index: n20 D 1.47 Solubility: insoluble Vapor Density: 4.7 Vapor Pressure: < 3 mmHg Toxicity/ Hazards: Extremely Hazardous in case of eye contact or ingestion. Flammable Formula: CH2Cl2 Molar Mass: 84.93 g/mL Melting Point: -97oC Boiling Point: 39.8-40oC Density: 1.325 g/mol Vapor Density: 2.9 Vapor Pressure: 24.45 psi Solubility: 20g/L Toxicity/ Hazards: Contact can severely irritate and burn the skin and eyes. Possibly a carcinogen.
Formula: Na2SO4 Molar Mass: 142.04 g/mol Appearance: white crystalline solid Density: 2.664 g/cm3 Melting Point: 884oC Boiling Point: 429oC