NEET Coordination Compounds — Set 18

Question 1

Which of the following is a heteroleptic complex?

Accepted Answer

A heteroleptic complex has different types of ligands. $ \ce{[Co(NH3)5Cl]^2+} $ has $ \ce{NH3} $ and $ \ce{Cl^-} $, unlike $ \ce{[Co(NH3)6]^3+} $ (homoleptic).

Question 2

Which complex would turn colorless if all its ligands were replaced by $ \ce{CN^-} $?

Accepted Answer

$ \ce{[Ni(H2O)6]^2+} $ (Ni$^{2+}$, $ d^8 $) is colored (green) due to d-d transitions with weak field $ \ce{H2O} $. With strong field $ \ce{CN^-} $ (e.g., $ \ce{[Ni(CN)6]^4-} $), it becomes low spin (diamagnetic), no d-d transitions, colorless.

Question 3

How many moles of $ \ce{AgCl} $ precipitate when 1 mole of $ \ce{[Fe(NH3)5Cl]Cl2} $ reacts with excess $ \ce{AgNO3} $?

Accepted Answer

In $ \ce{[Fe(NH3)5Cl]Cl2} $, the 2 $ \ce{Cl^-} $ ions outside the coordination sphere are ionizable and form $ \ce{AgCl} $, while the inner $ \ce{Cl} $ is a ligand. Thus, 2 moles precipitate.

NEET Chemistry: Coordination Compounds — Practice Set 18

Q1. Which of the following is a heteroleptic complex?

Q2. Which complex would turn colorless if all its ligands were replaced by \( \ce{CN^-} \)?

Q3. How many moles of \( \ce{AgCl} \) precipitate when 1 mole of \( \ce{[Fe(NH3)5Cl]Cl2} \) reacts with excess \( \ce{AgNO3} \)?

Q4. What is the ratio of \( e_g \) to \( t_{2g} \) electrons in \( \ce{[Fe(H2O)6]^2+} \) with Fe in +2 state? (Fe atomic number = 26)

Q5. Which complex exhibits geometrical isomerism?

Q6. What is the IUPAC name of \( \ce{[Cr(NH3)5NO2]Cl2} \)?

Q7. Which complex exhibits optical isomerism?

Q8. What is the oxidation state of cobalt in \( \ce{[Co(H2O)6]SO4} \)?

Q9. Which complex has a \( d^8 \) metal ion that prefers square planar geometry over tetrahedral with strong field ligands?

Q10. The EAN of Cr in \( \ce{[Cr(NH3)5Cl]^2+} \) is: (Cr atomic number = 24)