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Answer the following. (Class 12 Chemistry 2026, Q18)

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ChemistryCBSE Class 12 · Board exam 2026, set 56/5/1 · 2 marks · Very short answer

CBSE Class 12 Chemistry 2026: question 18

Set in the CBSE Class 12 board exam of 2026, paper 56/5/1, section B, question 18, for 2 marks. Try it first; the hints and our step-by-step solution are below.

Q18 · 2 marks · Very short answerElectrochemistry

Answer the following.

  1. (a)

    Name the cell which was used in the Apollo space programme for providing electrical power.

    1 mark
  2. (b)

    Define limiting molar conductivity.

    1 mark

Source: official question paper from cbse.gov.in (PDF). See it in the full 2026 board paper, set 56/5/1.

Hints

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

Hint 1

The Apollo cell combined hydrogen and oxygen and also gave drinking water.

Hint 2

Molar conductivity increases on dilution; think about its value at the dilution limit.

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. (a) The – fuel cell was used in the Apollo space programme to provide electrical power.

    1 mark

  2. (b) Limiting molar conductivity () is the molar conductivity of an electrolyte solution when its concentration approaches zero, i.e. at infinite dilution.

    1 mark

Answer: (a) H₂–O₂ fuel cell; (b) molar conductivity as concentration → 0 (infinite dilution)

Where the marks are

  • Names the fuel cell / H₂–O₂ fuel cell (1 mark)
  • Defines it as molar conductivity when concentration approaches zero (1 mark)

Revise the chapter

Practise this chapterBoard-style questions from Electrochemistry, one at a time, marked against the answer key and marking points.Back to the full paper2026 board paper, set 56/5/1: 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.