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The industrial process used… (Class 10 Science 2023, Q21B)

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ScienceCBSE Class 10 · Board exam 2023, set 31/4/1 · 2 marks · Very short answer

CBSE Class 10 Science 2023: question 21(B)

Set in the CBSE Class 10 board exam of 2023, paper 31/4/1, section B, question 21(B), for 2 marks. Try it first; the hints and our step-by-step solution are below.

Q21(B) · 2 marks · Very short answerAcids, Bases and Salts

The industrial process used for the manufacture of caustic soda involves electrolysis of an aqueous solution of compound 'X'. In this process, two gases 'Y' and 'Z' are liberated. 'Y' is liberated at cathode and 'Z', which is liberated at anode, on treatment with dry slaked lime forms a compound 'B'. Name X, Y, Z and B.

Source: official question paper from cbse.gov.in (PDF). See it in the full 2023 board paper, set 31/4/1.

Hints

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

Hint 1

The process is called the chlor-alkali process. Which aqueous solution is electrolysed?

Hint 2

One gas burns with a pop and the other is greenish-yellow. Which one forms at which electrode?

Hint 3

Which gas reacts with dry slaked lime to make a common disinfectant?

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. Caustic soda (NaOH) is made by the chlor-alkali process, the electrolysis of brine. So **X = sodium chloride, **.

    ½ mark

  2. The gas liberated at the cathode is **Y = hydrogen, **.

    ½ mark

  3. The gas liberated at the anode is **Z = chlorine, **.

    ½ mark

  4. Chlorine reacts with dry slaked lime to form **B = bleaching powder, **:

    ½ mark

Answer: X = NaCl, Y = , Z = , B = bleaching powder

Where the marks are

  • X = sodium chloride (½ mark)
  • Y = hydrogen (½ mark)
  • Z = chlorine (½ mark)
  • B = bleaching powder / (½ mark)

Revise the chapter

Practise this chapterBoard-style questions from Acids, Bases and Salts, one at a time, marked against the answer key and marking points.Back to the full paper2023 board paper, set 31/4/1: 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.