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Write the formula of… (Class 12 Chemistry SQP 2025-26, Q20)

questionbuddy.in/q/cbse-12-chemistry-2025-26-sqp-q20-formula-coordination-complex-diaquasilver

ChemistryCBSE Class 12 · Sample paper, session 2025-26 · 2 marks · Very short answer

CBSE Class 12 Chemistry sample paper 2025-26: question 20

From the official CBSE sample question paper for 2025-26, section B, question 20, for 2 marks. Try it first; the hints and our step-by-step solution are below.

Q20 · 2 marks · Very short answerCoordination Compounds

Write the formula of the following coordination complex:
I. diaquasilver(I) dichloridoargentate(I)
II. dihydroxidobis(triphenylphosphine)nickel(II)

Source: official sample paper from cbseacademic.nic.in (PDF). See it in the full Sample paper 2025-26.

Hints

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

Hint 1

The name ending in '-ate' is the anionic complex; the other part is the cationic complex.

Hint 2

Check the charges: Ag(I) and Ni(II), with OH⁻ and Cl⁻ as anionic ligands and PPh₃ and H₂O as neutral ones.

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 cation is [Ag(HO)] and the anion is [AgCl], so the formula is .

    1 mark

  2. II. Ni with two OH and two PPh ligands gives a neutral complex: .

    1 mark

Answer: I. [Ag(H₂O)₂][AgCl₂]; II. [Ni(OH)₂(PPh₃)₂]

Where the marks are

  • [Ag(H₂O)₂][AgCl₂] (1 mark)
  • [Ni(OH)₂(PPh₃)₂] (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 paperSample paper 2025-26: 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.