Coordination Compounds 15 Most Important Questions for Class 12 Chemistry Board Exam 2026

Coordination Compounds is one of the most important chapters for the Class 12 Chemistry Board Exam 2026. It has strong relevance in the final examination because questions from this chapter are asked every year in different formats such as short answers, long answers, and numericals. Students preparing for the Class 12 Chemistry Board Exam scheduled on 28 February 2026 must give special attention to this chapter during revision.

This topic is also important for competitive exams like JEE and COMEDK UGET. Many concepts from board preparation directly help in these exams.

The chapter includes important areas such as isomerism, hybridization, IUPAC naming, crystal field theory, magnetism, spectrochemical series, and electronic configuration. Students often feel that this chapter is lengthy. The reason is that it includes both theory and numerical problem solving. 

Here, you will find the 15 most important questions from Coordination Compounds for the Class 12 Chemistry Board Exam 2026. These questions are selected based on repeated board trends and core concepts that are commonly tested. Proper preparation of these questions will help students feel more confident before the Chemistry exam on 28 February 2026.

15 Most Important Coordination Compounds Questions for Class 12 Chemistry Board Exam 2026

Below are the most asked and most important questions from this chapter. Each question focuses on a core concept that is frequently tested in board exams.

Q1. When a co-ordination compound CrCl₃·6H₂O is mixed with AgNO₃, 2 moles of AgCl are precipitated per mole of the compound. Write the structural formula of the complex.

Q2. Write the IUPAC name of the complex [Cr(NH₃)₄Cl₂]Cl.

Q3. Write down the formula of: Tetraammineaquachloridocobalt(III) chloride.

Q4. What type of isomerism is exhibited by the complex [Co(en)3]^{3+}?

Q5. Identify the type of isomerism shown by [Co(NH3)6][Cr(CN)6].

Q6. What type of isomerism is exhibited by the complex [Co(NH3)3NO2]^{2+}?

Q7. On the basis of crystal field theory, write the electronic configuration for a d^5 ion with a strong field ligand where Delta_o > P.

Q8. Explain why [Ni(CO)_4] has tetrahedral geometry while [Ni(CN)4]^{2-} has square planar geometry, even though both are diamagnetic.

Q9. Using valence bond theory, predict the hybridization and magnetic character of [CoF6]^{3-}.

Q10. For the complex [NiCl4]2-, write:

(i) The IUPAC name

(ii) The hybridization type

(iii) The shape of the complex

(Atomic no. of Ni = 28)

Q11. For the complex [Fe(en)Cl2]Cl, identify the following:

(i) Oxidation number of iron

(ii) Hybrid orbitals and shape of the complex

(iii) Magnetic behaviour of the complex

(iv) Number of its geometrical isomers

(v) Whether there may be optical isomer also.

(vi) Name of the complex.

Q12. Write down the IUPAC name of the complex [Pt(en)2Cl2]^{2+}. What type of isomerism is shown by this complex? 

Q13. Draw the geometrical isomers of complex [Pt(en)2Cl2]^{2+}. 

Q14. (a) Write the formula for the following coordination compound: Bis(ethane-1,2-diamine) dihydroxidochromium(III) chloride

(b) Does ionization isomer for the following compound exist? Justify your answer: Hg[Co(SCN)4]

(c) Is the central metal atom in coordination complexes a Lewis acid or a Lewis base? Explain.

Q15. Out of the ligands "A", "B", "C" and "D", which ligand causes maximum crystal field splitting? Why?

OR

Which of the two, "A" or "D" will be a weak field ligand? Why?

Last Minute Preparation Tips for Class 12 Chemistry Coordination Compounds Chapter

Success in the chemistry board exam depends on smart revision and focus on high-weightage topics. Use these strategies to polish your understanding in the final days before the exam.

• Master IUPAC Naming: Practice the systematic rules for naming ligands alphabetically and stating oxidation states in Roman numerals.

• Understand Ligand Strength: Memorize the spectrochemical series to correctly predict if electrons will pair up or stay unpaired.

• Focus on Isomerism Rules: Remember that geometric isomerism usually requires at least two bidentate ligands to occur.

• Practice Structural Formulas: Frequently write out the formulas for complexes to avoid simple mistakes with brackets or ion placement.

• Use Visual Aids: Revise using mind maps and summary tables to keep the different types of isomerism clear in your mind.

• Solve Mock Questions: Work through previous year questions (PYQs) to get comfortable with the exam format and time limits.