Chemistry

Coordination Chemistry

325 Questions

Coordination chemistry focuses on coordination compounds, their structures, and their magnetic properties. The questions cover primary and secondary valencies, ligand types, and geometries of complexes. This topic is heavily tested in chemistry competitive exams and requires a good grasp of molecular structures.

primary and secondary valencycomplex geometriesligand field theorymagnetic properties of complexesisomerism in complexes

Coordination Chemistry Questions

Multiple choice

Complexes having bidentate ligands are known as

  1. co-ordination sphere

  2. chelates

  3. central metal atom or ion

  4. complex ion

Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Bidentate ligands are often referred to as chelating ligands because they can grab a metal atom in two places. A complex that contains a chelating ligand is called a chelate.

Multiple choice

The Quadruple bonds occurs in which of the followings compound?

  1. [Re2Cl8]--

  2. [Pt(Cl)2(PPh3)2]

  3. [Co(NH3)4Cl2]

  4. [Mn2(CO)10]

  5. None of these
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

This option is correct, because two Re atoms have eight electrons will occupy one sigma. Two pi and one delta bonding to form quadruple bonds between two Re atoms, i.e., Re-Re distance short to exist eclipsed form.

Multiple choice

In which category, the compound [Fe4C(CO)12]-2 belong to?

  1. Closo

  2. Nido

  3. Hypho

  4. Arachno

  5. None of these
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

This option is correct because in this carbonyl compound, total electron counts to be 62,  and electron used for non skeletal bonding is 48. Therefore skeletal electron pair available for frame work bonding 1/2[62 - 48]=7e pairs, i.e., m = 4,  hence occupies (4+3)e pairs,  predicted in (m+4) rule.

Multiple choice

Which of the following metal carbonyl absorbs lowest infrared frequency?

  1. [V(CO)6]-

  2. [Ti(CO)6]--

  3. [Mn(CO)6]+

  4. [Cr(CO)6]

  5. None of these
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

This option is correct,  because the two excess electron of metal ions shifted towards antibonding MOs of CO ligand resulting CO bond order is very low, due to this fact infrared frequency highly decreases.

Multiple choice

Which of the following pair of coordination compound has same magnetic moments?

  1. [Mn(CN)2(NH3)4], [Fe(CN)3(H2O)3]

  2. K2[Co(Cl)2(OH)2(NH3)2], [Zn(H2O)2(Py)2(NO2)2]

  3. [V(C2H5O)2(en)2], [Ni(CN)2(NH3)4]

  4. [Fe(CN)3(NH3)3] [Cr(CO)3(Cl)3]

  5. Both 1 and 2
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

This option is correct, because the central metal ions of both the compounds have same (five) unpaired electron in their d-orbitals, on basis of this fact both compounds show the same magnetic moment.

Multiple choice

Which pair of 'coordination complex: IUPAC name’ is not correctly matched?

  1. [Co(NH3)5ONO]2+: pentaamminenitritocobalt(III) ion

  2. K3[Co(C2O4)3]: potassium trioxalatocobaltate(II)

  3. [Cr(NH3)6][IrCl6]: hexaamminechromium(III) hexachloroiridate(III)

  4. [Cr(H2O)5Br]SO4: pentaaquabromochromium(III) sulphate

  5. [Cu(H2O)4]SO4: tetraaquacopper(II) sulphate
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The correct IUPAC name of K3[Co(C2O4)3] complex is potassium trioxalatocobaltate(III).

Multiple choice

Which of the following combinations of ‘limiting radius ratio: coordination number- shape’ is not correctly matched?

  1. < 0.155 : 2- linear

  2. 0.155 - 0.225 : 3- triangular planar

  3. 0.225 – 0.414 : 4- tetrahedral

  4. 0.414 – 0.732 : 4- square planar

  5. 0.732 – 0.999 : 6- octahedral
Reveal answer Fill a bubble to check yourself
E Correct answer
Explanation

For coordination number 6 the shape is octahedral with limiting radius ratio of 0.414 – 0.732. The radius ratio 0.732 – 0.999 is limiting for coordination number 8 with cubic shape.

Multiple choice

Which pair represents ionization isomers only?

  1. [Pt(NH3)4] [PtCl4] and [PtCl(NH3)3] [PtCl3(NH3)]

  2. [Co(NH3)6] [Cr(CN)6] and [Cr(NH3)6] [Co(CN)6]

  3. [Cr(H2O)6]Cl3 and [Cr(H2O)5Cl]Cl2.H2O

  4. [Co(NO2)(NH3)5]Cl2 and [Co(ONO)(NH3)5]Cl2

  5. [CoCl2(NH3)4]NO2 and [Co(Cl)(NO2)(NH3)4]Cl
Reveal answer Fill a bubble to check yourself
E Correct answer
Explanation

[CoCl2(NH3)4]NO2 and [Co(Cl)(NO2)(NH3)4]Cl both complexes are ionization isomers.