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Carry out the following… (Class 10 Science 2023, Q34b)

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ScienceCBSE Class 10 · Board exam 2023, set 31/5/1 · 5 marks · Long answer

CBSE Class 10 Science 2023: question 34(b)

Set in the CBSE Class 10 board exam of 2023, paper 31/5/1, section D, question 34(b), for 5 marks. Try it first; the hints and our step-by-step solution are below.

Q34(b) · 5 marks · Long answerCarbon and its Compounds

Carry out the following conversions, stating the condition(s) for each :

  1. (i)

    Ethanol Ethene

    0 marks
  2. (ii)

    Ethene Ethane

    0 marks
  3. (iii)

    Ethane Chloroethane

    0 marks
  4. (iv)

    Ethanol Ethanoic acid

    0 marks
  5. (v)

    Ethanoic acid Ethyl ethanoate

    0 marks

Source: official question paper from cbse.gov.in (PDF). See it in the full 2023 board paper, set 31/5/1.

Hints

Open one hint at a time and try again before the next.

Hint 1

Removing water from ethanol gives a double bond. Which reagent removes water?

Hint 2

Adding H₂ across a double bond needs a metal catalyst.

Hint 3

Replacing H by Cl in an alkane needs light, and an ester forms from an acid plus an alcohol.

Step-by-step solution

Each step shows the marks it earns, as an examiner would award them. Checked by an independent re-solve from the question paper.

  1. (i) Heating ethanol at 443 K with excess conc. (dehydration):

    1 mark

  2. (ii) Adding hydrogen in the presence of a nickel or palladium catalyst (hydrogenation):

    1 mark

  3. (iii) Reacting ethane with chlorine in the presence of sunlight (substitution):

    1 mark

  4. (iv) Oxidation with alkaline or acidified :

    1 mark

  5. (v) Warming ethanoic acid with ethanol in the presence of conc. (esterification):

    1 mark

Answer: (i) hot conc. H₂SO₄, 443 K; (ii) H₂ with Ni/Pd; (iii) Cl₂ in sunlight; (iv) acidified K₂Cr₂O₇ / alkaline KMnO₄; (v) ethanol + conc. H₂SO₄, warm

Where the marks are

  • Ethanol → ethene with hot conc. H₂SO₄ at 443 K (1 mark)
  • Ethene → ethane by H₂ with Ni/Pd catalyst (1 mark)
  • Ethane → chloroethane with Cl₂ in sunlight (1 mark)
  • Ethanol → ethanoic acid with an oxidising agent (1 mark)
  • Ethanoic acid → ethyl ethanoate with ethanol and conc. H₂SO₄ (1 mark)

Revise the chapter

Practise this chapterBoard-style questions from Carbon and its Compounds, one at a time, marked against the answer key and marking points.Back to the full paper2023 board paper, set 31/5/1: every question, by section.

The question is transcribed from the official paper; figures are described in words. The solution, hints and chapter tag are ours. Spotted an error? Write tosupport@questionbuddy.in.