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Introduction

IDENTIFICATION OF AN ORGANIC UNKNOWN When doing each procedure, take extra care and wear eye protection, gloves, and lab coat because there's a high risk due to the organic chemical been unknown. Risk assessment before the test alkene and phenol: Procedure / Chemical Risk Precaution Information derived from Bromine water Toxic: very toxic by inhalation. Irritant: irritant to skins and eyes Harmful: by inhalation, contact with skin or swallowed. If swallowed, wash out mouth and drink a glass or two of water. Seek medical attention as soon as possible. If inhaled, remove victim and put where there's fresh air. If chemical gets into eyes, wash off with plenty of water and seek medical help. Wear eye protection and gloves during handling. Dispose using fume cupboard. Cleapss card page number 15 Unknown organic compound Explosive: risk of explosion by shock, friction, fire, or other source of ignition. Toxic: by inhalation or if swallowed. And it's very toxic to skin. Skin stain yellow on contact with which may be followed by dermatitis. If swallowed, wash out mouth and drink a glass or two of water. Seek medical attention as soon as possible. If inhaled, remove victim and put where there's fresh air. If chemical gets into eyes, wash off with plenty of water and seek medical help. Wear eye protection, and wear gloves during handling of chemical. If chemical is in a bottle, open slowly and keep damp at all times. Test 1: Alkene Shake the unknown compound with a few drops of bromine water. If solution changes colour from orange to colourless then an alkene is present. However if a negative result is observed where colour change doesn't occur, then proceed to the next test. Test 2: Phenol Pipette 2ml of bromine water into a test tube and add a few drops of the unknown compound to it and gently shake. For a positive result, bromine water will decolourise and white precipitate forms, this indicates phenol is present. ...read more.

Middle

If chemical is in a bottle, open slowly and keep damp at all times. http://www.jtbaker.com/msds/englishhtml/P5719.htm Test 6: Carboxylic acids / Alcohols Add few drops of unknown compounds to blue litmus paper. It the unknown is a carboxylic acid, colour of the litmus paper will change from blue to red. But if it's an alcohol, the colour of the litmus paper will remain blue so proceed to test 7 and 8 to distinguish between primary and tertiary alcohol. Risk assessment before doing the test for both primary and tertiary alcohols: Procedure / Chemical Risk Precaution Information derived from Acidified potassium dichromate Poison! Danger! May be fatal if swallowed, inhaled or absorbed through skin. Strong oxidizer. Contact with other material may cause a fire. Corrosive. Causes severe burns to every area of contact. Affects the respiratory system, liver, kidneys, eyes, skin and blood. May cause allergic reaction. Cancer hazard. Can cause cancer. Risk of cancer depends on duration and level of exposure. If swallowed, wash out mouth and drink a glass or two of water. Seek medical attention as soon as possible. If inhaled, remove victim and put where there's fresh air. If chemical gets into eyes, wash off with plenty of water and seek medical help. Wear eye protection, and wear gloves during handling of chemical. If chemical is in a bottle, open slowly and keep damp at all times. http://www.jtbaker.com/msds/englishhtml/P5719.htm Boiling bath Hot water can burn the skin Stay quite away from it and avoid playing near it Bunsen burner Heat can cause serious damage to skin. Don't play with fire; take special care when using the Bunsen burner. Unknown organic compound Poison! Danger! May be fatal if swallowed, inhaled or absorbed through skin. Strong oxidizer. Contact with other material may cause a fire. Corrosive. Causes severe burns to every area of contact. Affects the respiratory system, liver, kidneys, eyes, skin and blood. May cause allergic reaction. ...read more.

Conclusion

On the mass spectrum, the M+ which has the mass that is equal to the Mr of compound F is 88 hence, the Mr of compound F an ester is 88. The structure of the ester can be deduced from this. Analysing the infrared spectroscopy shows a strong absorption peak at approximately 1720cm-1. this peak indicates the presence of a C=O functional group which can be found in esters. Nuclear magnetic resonance spectroscopy (NMR), which determines the structure of compounds shows peak at different chemical shift values (ppm). This provides information on the different groups present and how they are bonded together in a molecule. Proton attached to oxygen will not split in a high resolution NMR. The information derived from the NMR is: Chemical shift (ppm) Number of proton pattern (intensity) Relative splitting Identity 1.2 3H Triplet CH3 2.3 2H Quartet CH2 3.6 3H Singlet CH3 From the splitting pattern of the 3 peaks, the chemical shift on 1.2 with a triplet splitting must be adjacent to a CH2, and the chemical shift on 2.3 with a quartet splitting must be adjacent to a CH3 and the chemical shift on 3.6 with a singlet splitting must be adjacent to a C. Using the information derived from the NMR spectrum, I suggest the skeletal formula of compound F is: Ethyl ethanoate (an ester) The Mr of ethyl ethanoate is 88 which is equal to the MR derived from the mass spectrum. Mr of ethanal is C4H8O2 (4�12) + (8�1) + (16�2) =88 The information from all three spectra supports the original findings of the chemical tests and has given details on the structure of the ester and the exact identity of compound F is established as ETHYL ETHANOATE. BIBLOGRAPHY 1. Eccles, H (2001) AS Revision Guide Heinneman (pages 64-65) 2. Earl, B & Wilford LDR (2001) Further Advanced Chemistry. John Murray Publishers (pages 136-141 & page 228) 3. Ratcliff, B (2000) Chemistry 1. Cambridge University Press (pages 133-134) 4. Ratcliff, B (2001) Chemistry 2. Cambridge University Press (pages 24-25 & 66-67) 5. http://www.docbrown.info/page13/ChemicalTests/ChemicalTests.htm ?? ?? ?? ?? ...read more.

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