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The melting and boiling… (Class 10 Science 2024, Q22)

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ScienceCBSE Class 10 · Board exam 2024, set 31/5/1 · 2 marks · Very short answer

CBSE Class 10 Science 2024: question 22

Set in the CBSE Class 10 board exam of 2024, paper 31/5/1, section B, question 22, for 2 marks. Try it first; the hints and our step-by-step solution are below.

Q22 · 2 marks · Very short answerCarbon and its Compounds

The melting and boiling points of carbon compounds are generally low and they are largely non-conductors of electricity. State two conclusions based on these two properties.

Source: official question paper from cbse.gov.in (PDF). See it in the full 2024 board paper, set 31/5/1.

Hints

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

Hint 1

Melting and boiling need the molecules to be pulled apart. What does a low temperature tell you about the forces holding them together?

Hint 2

Electric conduction needs charged particles. Think about what type of bond, sharing or transfer of electrons, gives no ions.

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. Low melting and boiling points: the forces of attraction between the molecules of carbon compounds are weak, so little energy is needed to separate them.

    1 mark

  2. Non-conductors of electricity: the atoms in carbon compounds are held by covalent bonds (sharing of electrons), so no ions or charged particles are formed to carry current.

    1 mark

Answer: (1) Intermolecular forces in carbon compounds are weak. (2) Their bonding is covalent, so no ions are formed.

Where the marks are

  • Concludes that intermolecular forces of attraction are weak (1 mark)
  • Concludes that bonding is covalent, so no ions are formed and the compounds cannot conduct (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 paper2024 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.