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

The aim of the experiment is to identify 6 unknown colourless liquids by carrying out different chemical reactions on each of the liquids.

Extracts from this document...


The aim of the experiment is to identify 6 unknown colourless liquids by carrying out different chemical reactions on each of the liquids. Flow chart showing tests/ reactions to identify the liquids. a) Bromoethane b) Butan-1- ol c) Cyclohexene d) Ethanoic Acid e) 2-Methylpropan-2-ol f) Water a b c d e f Forms CO2 gas and a white precipitate when reacting with sodium hydrogen carbonate. Yes No d- Ethanoic Acid a b c e f Decolourises bromine water Yes No c- Cyclohexene a b e f Forms a pale cream precipitate when reacting with silver nitrate solution. Yes No a- Bromoethane b e f Colour change occurs from orange to green when reacting with acidified potassium dichromate (vi) Yes No b- Butan-1-ol e f Turns blue cobalt chloride paper pink Yes No f- Water e Reacts with concentrated Hydrochloric acid, and Chlorine is substituted in place of the OH group. It then reacts with bromine water, decolourising the solution. Yes e- 2-Methylpropan-2-ol Background Information & Methods for Testing: Haloalkanes: Bromoethane is a haloalkane. Haloalkanes have the general formula of CnH2n+1X where the X represents the halogen. Bromoethane is a primary haloalkane. ...read more.


Equation for the reaction: K2CR2O7/H+ CH3CH2CH2CH2OH CH3CH2CH2CHO Butan-1-ol Heat [-2H] Butanal 2-Methylpropan-2-ol is a Tertiary Alcohol. Carbon2 has no hydrogen atoms, but has 3 alkyl groups and one OH group attached instead. Molecular Formula: C4H9OH = CH3CCH3OHCH3 Structural formula of 2-Methylpropan-2-ol: Carbon2 OH group Alkyl group To identify the tertiary alcohol, I will react 5cm3 of the liquid with 2cm3 of hydrochloric acid in a boiling tube and leave it at room temperature for 10 minutes. The tertiary alcohol will now have become a haloalkane because chlorine has replaced the OH group. After 10 minutes, I will react each of the liquids with bromine water. The solution that will decolourise will show that the original solution used was the tertiary alcohol, 2-Methylpropan-2-ol. (3) Equation for the reaction: HCl (aq) CH3CCH3OHCH3 CH3CCH3ClCH3 + H2O 2-Methylpropan-2-ol 2-Methyl-chloro-propane Water Carboxylic Acids: Ethanoic Acid is a Carboxylic Acid. Carboxylic acids are weak acids, hence only small amounts of its molecules dissociate in water. Carboxylic acids are however, stronger than alcohols due to the weakening of the O-H bond in the acid because of the presence of the carbonyl group and also because of the stability of the anion formed when the H+ ion leaves. ...read more.


If the solution decolourises, it will indicate that the original liquid used was Cyclohexene.(2) Equation for the reaction: C6H10 + Br2 C6H10Br2 Cyclohexene Bromine 1, 2-dibromohexane Water: Water is a pure substance made up of 2 hydrogen atoms and one oxygen atom. Water makes up 70% of the body and is very important to human life. Molecular Formula: H2O Structural Formula of Water: Oxygen atom. Hydrogen atoms To identify water, I will react 10cm3 the unknown substance in a beaker with blue cobalt chloride paper. If the paper turns pink after being in contact with the solution, it will prove the solution is water. The blue colour in the cobalt chloride paper is because of [CoCl4]2- ions. The blue [CoCl4]2- ions convert into [Co(H2O)6]2+ ions, which are pink in colour. (1) Safety: Source of hazard Hazard Precautions taken Acidified potassium dichromate (vi) Breathing in toxic fumes Conduct tests in a fume cupboard. Mixing chemicals Chemical may splash into eyes Wear safety goggles Acids Spillage/ contact with body Wear gloves and lab coat Apparatus: 6 boiling tubes Test tube holder Water bath 25cm3 beaker Measuring cylinder Spatula Bung Plastic tubing Silver nitrate Dilute alkali solution in ethanol Nitric acid Acidified potassium dichromate (VI) Hydrochloric acid Bromine water Sodium hydrogen carbonate (powdered) Limewater Blue cobalt chloride paper Six unidentified liquids- Bromoethane, Butan-1- ol, Cyclohexene, Ethanoic Acid, 2-Methylpropan-2-ol, Water. ...read more.

The above preview is unformatted text

This student written piece of work is one of many that can be found in our GCSE Classifying Materials 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 GCSE Classifying Materials essays

  1. Marked by a teacher

    rates of reaction- hydrochloric acid

    3 star(s)

    indirectly proportional because if it was a straight line it would have been directly proportional which means the rate of reaction would have doubled every time. I put gradients on every graph so I could compare the steepness on the line so I could conclude my results.

  2. Marked by a teacher

    In this CDA I will write about how plastic bags are made, why plastic ...

    If they wanted something stronger, they have the option of buying bags that aren't made of plastic such as the 'Tesco bag for life'. It would possibly help if there were more recycling bins put in place in public areas such as parks, shopping centres etc, as many people may

  1. Peer reviewed

    Rate of reaction between Calcium Carbonate and Hydrochloric Acid

    4 star(s)

    Manual errors were also a major reason for the inaccuracy. Levels of HCL were read by eye resulting in minor inaccuracy. Stopping of the stopwatch was also done manually leading to minor inaccuracy. Also a small amount of CO2 was released in the time gap of adding the marble

  2. Rate of reaction of hydrochloric acid on magnesium.

    The gradient shows the actual speed of the whole reaction. The graph 0.6M the gradient was 0.46cm3/s this is almost three times the amount for the 0.3M graph (0.15cm3/s) accordingly this tells me if the concentration is doubled the gradient increases three times more this declares the fact how the concentration of an acid influences the rate of the reaction.

  1. The rates of reaction between CaCO3 and HCL

    Conclusion: The aim of the investigation was find out which of two samples of limestone was purist. The sample found to be purer by the data collected is west. The proof of this is. * From the graph, the curve of the graph follows the proven reaction curve.

  2. Identification of an unknown compound.

    A further test that could be carried out would involve recrystallisation of the orange/red 2,4-dinitrophenylhydrazone precipitate that was formed in test 2. Following recrystallisation, the melting point of this precipitate would be found. This extension of test 2 would show the exact aldehyde, compound B is (as melting points of aldehydes are unique).

  1. Finding the empirical formula of aluminium chloride.

    silver ions react with the chloride ions according to the following reaction: Ag+(aq) + Cl-(aq) AgCl (s) Hence from the stoichiometry, we find that the ratio n Ag+ : n Cl- is 1:1 ? n Cl- = n Ag+ = 2.2375 x 10-3 mol 3.

  2. Flow Chart Showing Tests to Identify All 8 Chemicals

    are made of a carbonyl group bonded to two carbon atoms from an aryl/ alkyl group. Ketones are soluble in water because the carbonyl can interact with water by hydrogen bonding. However ketones cannot bond to hydrogen and are hydrogen atom acceptors, not donators.

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