• Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

Identification of an organic unknown

Extracts from this document...

Introduction

Identification of an organic unknown Aim In this piece of coursework I will be outlining a sequence of simple chemical tests to use to identify 8 different functional groups. These functional groups I will be finding are, Alkene, primary alcohol, tertiary alcohol, aldehyde, ketone, carboxylic acid, ester and phenol. I will be explaining the tests, the observations and the safety of each test/functional group. Wet Tests Bromine water In the presence of an Alkene, the bromine water will turn the unknown from orange to colourless. C2H4(L) + Br2(L) C2H4Br2(L) In the presence of a phenol group, a white precipitate will be formed when bromine water is added.7 Phenol(L) + 3Br2(L) 2, 4, 6-tribromophenol(L) + 3HBr(L) Principal hazards Bromine vapour is released from bromine water solutions when they are open to the air. This vapour is harmful if inhaled. Bromine water is harmful if you swallow it and can cause eye damage if splashed into the eyes. Prolonged contact with the skin may lead to burns. Safe handling Wear safety glasses. Work in a well ventilated area. Do not leave bromine water in the open laboratory, unless the solution is covered to prevent vaporization of bromine. Emergency Eye contact: Immediately flush the eye with water. If irritation persists, call for medical help. ...read more.

Middle

This is not likely to be harmful, nor will it be permanent, but may be unsightly. There is a small risk of forming explosive fulminating silver, if Tollen's reagent is left unused for a period of time. To avoid this, neutralise unused reagent with a little nitric acid and discard. Safe handling Wear safety glasses. Avoid skin contact. Emergency Eye contact: Immediately flush the eye with water. If irritation persists, call for medical help. Skin contact: Wash off immediately with soap and water. If swallowed: Call for medical help if the amount swallowed is not trivial. Disposal Small amounts can be neutralised with nitric acid (test with pH paper) and then flushed down the sink if local rules permit. Do not store unwanted reagent for long periods. Protective equipment Safety glasses. 3 Acidified potassium dichromate (VI) Strong oxidising agent. Distil organic unknown with potassium dichromate (VI). If colour change happens from orange to green, the functional group has allowed the primary alcohol in the unknown to be oxidised. 4 Principal hazards Potassium dichromate is toxic if swallowed, inhaled or absorbed through the skin. It is corrosive and may produce severe eye damage. Chromium (VI) compounds are carcinogens. Potassium dichromate may act as a sensitizer. This material is a strong oxidizing agent and reacts vigorously or explosively with a wide variety of reducing agents. ...read more.

Conclusion

Safe handling Wear safety glasses. It is important that you do not inhale phosphorus pentachloride, so work in a well-ventilated area, preferably using a fume cupboard. Clean up any spills immediately. Emergency Eye contact: Immediately flush the eye with water. If irritation persists, call for medical help. Skin contact: Wash off immediately with water; seek first aid if the skin appears red or damaged. If swallowed of inhaled: Call for immediate medical help. Disposal Store, properly labelled, for later disposal as solid waste or destruction. Protective equipment Safety glasses. 6 Sodium Carbonate Sodium carbonate added to an acid will neutralize the acid, and form carbonic acid, which is not stable and so decomposes to form CO2 which is then given off. The overall reaction is: Na2CO3 + 2HCl ---> 2Na+ + 2Cl- + H2O + CO2 Adding sodium carbonate to an ester creates a fruity smell. No observant change formed. Acid + alcohol ester + water Principal hazards ** Sodium carbonate powder may irritate the lungs if you breathe it in. Safe handling Wear safety glasses if required by local rules. Emergency Eye contact: Immediately flush the eye with water. If irritation persists, call for medical help. Skin contact: Wash off with water. If swallowed: Call for medical help if the amount swallowed is large. Disposal Small amounts of sodium carbonate can be flushed down the sink unless local rules prohibit this. Protective equipment Safety glasses if required. ...read more.

The above preview is unformatted text

This student written piece of work is one of many that can be found in our AS and A Level Organic Chemistry section.

Found what you're looking for?

  • Start learning 29% faster today
  • 150,000+ documents available
  • Just £6.99 a month

Not the one? Search for your essay title...
  • Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

See related essaysSee related essays

Related AS and A Level Organic Chemistry essays

  1. Find the enthalpy change of combustion of a number of alcohol's' so that you ...

    To improve this I could have used a more accurate thermometer, which is measured to the nearest O.10C and leave it in the water for 5 minutes to get a true initial temperature and to minimise error. This would improve the value for both the enthalpy change of combustion and

  2. The aim of this experiment is to produce Aspirin. This is an estrification in ...

    * The crystalline mush was diluted by adding 8cm3 of cold glacial ethanoic acid using a 10cm3 pipette and cooled by placing in a water bath containing crushed ice (product becomes less soluble when its cool). This was left for approximately 10 - 15 minutes until an impure solid was formed.

  1. Compare the enthalpy changes of combustion of different alcohols

    I will use the average measurements for Methanol to illustrate how I calculated the enthalpy change of combustion for Methanol. The sum I used was: ? Enthalpy (KJ/mol) = Q (KJ) / Amount of Moles burned = 13.65 KJ / 0.04 Moles = 341.25 KJ/mol This is different to the

  2. investigating the amount of ascorbic acid present in fruit

    Preparing the 10% Acetic Acid: 1. Make sure that the balance is set to 0.00g. 2. Get the weighing boat and weigh out 10.00g of solid acetic acid. 3. Measure 90cm3 of distilled water in a plastic 100cm3 measuring cylinder and making sure that it reaches the meniscus and the

  1. Comprehensive and Detailed Chemistry notes

    needed (closed vessels, absence of air -- A micro-organism such as yeast which contains enzymes to catalyse the reaction * summarise the chemistry of the fermentation process -- Simple sugars derived from plant material are mixed with yeats -- Yeats produces the enzymes; zymase, multase and invertase -- These enzymes

  2. Chemistry Investigation - How does chain length affect: ∆Hcè for alcohols?

    In both the experiments the water volume remained constant at 100cm3, as did the 10C temperature rise that dictated the end of the experiment. I measured in both cases the change in mass of the fuel I used to allow preliminary analysis.

  1. Comparing the enthalpy changes of combustion of different alcohols

    Secondly, I can deduce that the more oxygen atoms present in a molecule, the less energy it will give out when it combusts. This means that oxygenated fuels such as alcohols and ethers are less energy-rich than hydrocarbon fuels. Prediction I predict that the more carbon atoms there are in the alcohol, its enthalpy change of combustion will increase.

  2. Qualitative Analysis (A combined approach using spectroscopic and chemical analysis for structural identification of ...

    A Prissian blue precipitate would be observed if nitrogen is present. (Procedure B) 2 drops of ammounium polysulphide solution was added to 2 ml of the stock solution. The mixture was evaporated to dryness on a steam bath. Then 5 ml of dilute hydrochloric acid was added, the solution was warmed and filtered.

  • Over 160,000 pieces
    of student written work
  • Annotated by
    experienced teachers
  • Ideas and feedback to
    improve your own work