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During oxidation of ethanol to ethanol, the ethanol formed was found to be contaminated with unconverted ethanol, describe how you would obtain ethanal free from ethanol​

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Answer:

Ethanol is oxidised by acidified sodium dichromate in a test tube reaction, firstly to form ethanal (acetaldehyde), and with further oxidation, ethanoic acid (acetic acid)

Procedure

Place about 3 cm3 of acidified sodium dichromate solution in a boiling tube.

Use a teat pipette to add 5–7 drops of ethanol, with shaking.

Cool the mixture in the tube under a tap. Note the sweetish smell of ethanal (acetaldehyde) at first, then becoming sharper as oxidation continues and forms ethanoic acid (acetic acid).

When the reaction has subsided, the mixture can be warmed gently; the smell of ethanoic acid will become more noticeable.

The process of how we would obtain ethanal free from ethanol is described in the explanations below.

  • In Chemistry, Ethanol undergoes oxidation in the presence of sodium dichromate plus sulphuric acid to yield ethanal and water.

The procedure for achieving this in the laboratory is as follows;

  • Step 1; Measure a quantity of a solution of sodium dichromate acidified in a dilute sulphuric acid and pour into a test tube.

  • Step 2; Add excess ethanol. This is because if we don't do so there will be plenty of oxidizing agent to carry out a second operation which changes the aldehyde to ethanoic acid. However, we need only the aldehyde.

  • Step 3; When the aldehyde ethanal begins to form which will be evident by the change in the colour of solution from orange to green, then the mixture should be distilled from the test tube and tbethe aldehyde collevted so that it doesn't undergo additional oxidation into ethanoic acid.

Read more at; https://brainly.in/question/18574624

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