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Answer the following. (Class 12 Chemistry 2025, Q19b)

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ChemistryCBSE Class 12 · Board exam 2025, set 56/7/1 · 2 marks · Very short answer

CBSE Class 12 Chemistry 2025: question 19(b)

Set in the CBSE Class 12 board exam of 2025, paper 56/7/1, section B, question 19(b), for 2 marks. Try it first; the hints and our step-by-step solution are below.

Q19(b) · 2 marks · Very short answerCoordination Compounds

Answer the following.

  1. (i)

    Write the formula of the following coordination compound : Pentaamminecarbonatocobalt(III)chloride

    1 mark
  2. (ii)

    Write the IUPAC name of the linkage isomer of the complex .

    1 mark

Source: official question paper from cbse.gov.in (PDF). See it in the full 2025 board paper, set 56/7/1.

Hints

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

Hint 1

Carbonate carries a charge of −2; use it to decide how many chloride ions are needed.

Hint 2

The ligand is ambidentate: it can bind through N or through O.

Hint 3

Name the isomer in which the donor atom is O.

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) The carbonate ion is a −2 ligand and Co is +3, so the complex ion is . One chloride balances it: .

    1 mark

  2. (ii) In the given complex, is bonded through N (nitrito-N). Its linkage isomer is , in which the ligand is bonded through O. Its name is Pentaamminenitrito-O-cobalt(III) chloride.

    1 mark

Answer: (i) ; (ii) Pentaamminenitrito-O-cobalt(III) chloride

Where the marks are

  • Correct formula (1 mark)
  • Correct name of the O-bonded linkage isomer (1 mark)

Revise the chapter

Practise this chapterBoard-style questions from Coordination Compounds, one at a time, marked against the answer key and marking points.Back to the full paper2025 board paper, set 56/7/1: 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.