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A metal 'M' on reacting with… (Class 10 Science 2023, Q28b)

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ScienceCBSE Class 10 · Board exam 2023, set 31/6/1 · 3 marks · Short answer

CBSE Class 10 Science 2023: question 28(b)

Set in the CBSE Class 10 board exam of 2023, paper 31/6/1, section C, question 28(b), for 3 marks. Try it first; the hints and our step-by-step solution are below.

Q28(b) · 3 marks · Short answerMetals and Non-metals

A metal 'M' on reacting with dilute acid liberates a gas 'G'. The same metal also liberates gas 'G' when reacts with a base.

  1. (i)

    Write the name of gas 'G'.

    0 marks
  2. (ii)

    How will you test the presence of this gas?

    0 marks
  3. (iii)

    Write chemical equations for the reactions of the metal with (1) an acid and (2) a base.

    0 marks

Source: official question paper from cbse.gov.in (PDF). See it in the full 2023 board paper, set 31/6/1.

Hints

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

Hint 1

Metals such as zinc react with both acids and bases. Which gas is released in both cases?

Hint 2

The salt formed with NaOH is sodium zincate.

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) Gas G is hydrogen (). Metal M is an amphoteric metal such as zinc.

    ½ mark

  2. (ii) Test: bring a burning splinter or matchstick near the gas. It burns with a pop sound, which confirms hydrogen.

    ½ mark

  3. (iii)(1) With an acid:

    1 mark

  4. (iii)(2) With a base: (sodium zincate).

    1 mark

Answer: (i) Hydrogen; (ii) burns with a pop sound; (iii) Zn + 2HCl → ZnCl₂ + H₂; Zn + 2NaOH → Na₂ZnO₂ + H₂

Where the marks are

  • Names hydrogen (½ mark)
  • Pop-sound test (½ mark)
  • Balanced equation of metal with acid (1 mark)
  • Balanced equation of metal with base (1 mark)

Revise the chapter

Practise this chapterBoard-style questions from Metals and Non-metals, one at a time, marked against the answer key and marking points.Back to the full paper2023 board paper, set 31/6/1: 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.