As part of a Chemistry practical, I had to five different tests for things, and note down the result. Unfortunately, at least several results were incorrect, and despite hours of research, I cannot fully determine what I was supposed to observe and why.

Part 1 – A test for an alcohol.

  1. To approximately 1 cm3 of ethanol in a dry test tube, add a small piece of metallic sodium.
  2. Record your observations.
  3. Make sure that you dispose safely of any excess sodium using the beaker of ethanol provided.

The liquid turned cloudy white. I can't find any discernible reason why this would be, unless sodium ethoxide is milky white, precipitate or dissolved. Should it just have released bubbles?

Part 2 – A test for an aldehyde using Fehling’s solution.

  1. In a clean test tube mix together equal volumes of Fehling's solution A and Fehling's solution B. The resultant Fehling's test reagent should be a clear dark blue solution.
  2. Add 5 drops of this test reagent to 1 cm3 of sodium carbonate solution in a test tube containing a few anti-bumping granules and then add 1 cm3 of ethanal (or propanal) to this same test tube.
  3. Warm the test tube gently for approximately two minutes in a beaker half-filled with hot water and then gradually bring the beaker of water to boiling and maintain this temperature for a few minutes.
  4. Using the test tube holder, carefully lift the test tube out of the boiling water and allow its contents to stand for several minutes.
  5. Record your observations.

The liquid turned murky green. My understanding is that it's supposed to be red? I'd love to have a chemical equation for this as well.

Part 3 – A test for an alkene (a test for unsaturation)

  1. To approximately 1 cm3 of cyclohexene in a test tube, add an equal volume of bromine water and shake the contents of the tube vigorously from side to side.
  2. Record your observations.

The liquid went colourless. This one went as expected, I believe. My understanding is that it went colourless because all the bromine reacted?

Part 4 – A test for a carboxylic acid

  1. Place one small spatula measure of solid sodium hydrogencarbonate in a test tube and add to it approximately 2 cm3 of dilute ethanoic acid.
  2. Record your observations.

The liquid produced bubbles, went cloudy, then went colourless. No explanation here.

Part 5 – A test for a haloalkane.

  1. Using a teat pipette, add approximately 5 drops of 1-bromobutane to 1 cm3 of sodium hydroxide solution in a test tube. Warm the contents of the test tube for a few minutes, by placing it into a beaker filled with hot water at approximately 60 C.
  2. Acidify the contents of the test tube by adding 2 cm3 of dilute nitric acid and then add 1 cm3 of silver nitrate solution.
  3. Record your observations.

Produced a blue precipitate after the bromobutane was added, and went colourless after we added the silver nitrate solution. No explanation here either.

Not enough time has elapsed as of now, but I will put reputation on this, and award it to a sufficient answer as soon as I am able.

  • 1
    $\begingroup$ @GaurangTandon I'm at my question limit for Chemistry, and I really need all of these answered. $\endgroup$ – Piomicron Apr 29 '18 at 13:24
  • $\begingroup$ One additional reason your question may have attracted negative attention is that it was hard to read. In the future, try to avoid lots of bold text, and use more lists. I turned the questions into quotes using >. $\endgroup$ – pentavalentcarbon Apr 29 '18 at 13:38