Question 1

Hybridisation and geometry of [ Ni ( CN )_4 ]^ 2- are

Accepted Answer

In [ Ni ( CN )_4 ]^ 2- , Ni ^ 2+ =3 d^8 4 s^0 AsCN ^ - is a strong ligand, pairing of electrons take place, Therefore, d s p^2 hybridisation gives square planar geometry.

Question 2

Match List I with List II. array llll & c array c List I \( Complex ) array & & c array c List II \(Oxidation \ of metal) array \ A. & Ni ( CO )_4 & I. & +1 \ B. & [ Fe ( H _2 O )_5 NO ]^ 2+ & II.

Accepted Answer

The correct match is A-II, B-I, C-IV, D-III.

Question 3

Which of the following is correct order of ligand field strength?

Accepted Answer

The increasing order of field strength of ligands (according to spectrochemical series) S ^ 2- C _2 O _4^ 2- NH _3 en CO

Question 4

The correct statement among the following is;

Accepted Answer

Ferocene is Fe ( ^5- C _5 H _5 )_2 Perxenate ion is [ XeO _6 ]^4 which is octahedral.

Question 5

The type of isomerism present in nitropentammine chromium (III) chloride is

Accepted Answer

The chemical formula of nitropenta ammine chromium(III) chloride is: [ Cr ( NH _3 )_5 ( NO _2 ) ] Cl _2 It can exist in following two structures [ Cr ( NH _3 )_5 ( NO _2 ) ] Cl _2 and Pentaamminenitrochromium (III) chloride [ Cr ( NH _3 )_5 ONO ] Cl _2 Pentaamminenitritochromium (III) chloride Therefore, the type of isomerism found in this compound is linkage isomerism as NO _2 group is linked through N as - NO _2 or through O as ONO.

Question 6

Identify, from the following, the diamagnetic, tetrahedral complex

Accepted Answer

(a) Ni in [ Ni ( Cl )_4 ]^ 2- exist as Ni ^ 2+ ion. Cl is a weak field ligand (high spin). It will not cause pairing of electrons. Hence, configuration of [ Ni ( Cl )_4 ]^ 2- is Tetrahedral with two unpaired electrons (i.e., paramagnetic) and has s p^3 hybridisation. (b) In [ Co ( C _2 O _4 )_3 ]^ 3- , ( C _2 O _4 )_3^ 2- is a bidentate ligand thus, give octahedral structure. (c) In [ Ni ( CN )_4 ]^ 2- , Ni exist as Ni ^ 2+ ion. CN ^ - is a strong field ligand (low spin). Causes pairing of elect

Question 7

The chemical name of calgon is

Accepted Answer

Calgon is sodium hexametaphosphate with the formula Na _6 P _6 O _ 18 :

Question 8

The complex with highest magnitude of crystal field splitting energy ( _0 ) is

Accepted Answer

smaller cations prefer coordinate bonding due to greater polarizing power. Ti ^ +3 =67 pm radius, Cr ^ 3+ =62 pm radius Mn ^ +3 =65 pm radius, Fe ^ +3 =65 pm radius So, Cr ^ 3+ has highest tendency to attract ligand.

Question 9

IUPAC name of [ Pt ( NH _3 )_2 Cl ( NH _2 CH _3 ) ] Cl is

Accepted Answer

The complex is a cationic complex with two ammine ( NH _3 ), one chloro ( Cl ) and one methanamine ligand. Thus, the name will be :Diamminechloro (methanamine) platinum (II) chloride.

Question 10

Which of the following complexes will exhibit maximum attraction to an applied magnetic field?

Accepted Answer

Complex with maximum number of unpaired electron will exhibit maximum attraction to an applied magnetic field. [ Zn ( H _2 O )_6 ]^ 2+ d ^ 10 system t _ 2 ~g ^6 e _ g ^4 0 unpaired e ^ - [ Co ( H _2 O )_6 ]^ 2+ d ^7 system t _ 2 ~g ^ 5 e _ g ^2 3 unpaired e ^ - [ Co ( en )_3 ]^ 3+ d ^6 system t _ 2 ~g ^6 e _ g ^0 0 unpaired e ^ - [ Ni ( H _2 O )_6 ]^ 2+ d ^8 system t _ 2 ~g ^ 6 e _ g ^2 2 unpaired e

Question 11

The compounds [ PtCl _2 ( NH _3 )_4 ] Br _2 and [ PtBr _2 ( NH _3 )_4 ] Cl _2 constitutes a pair of

Accepted Answer

[ PtCl _2 ( NH _3 )_4 ] Br _2 and [ PtBr _2 ( NH _3 )_4 ] Cl _2 are ionisation isomers.

Question 12

Among the ligands NH _3, en, CN ^ - and CO the correct order of their increasing field strength, is :

Accepted Answer

Ligands can be arranged in a series in the orders of increasing field strength as given below: Weak field ligands: I ^ - Strong field ligands O ^ -- Such a series is termed as spectrochemical series. It is an experimentally determined series based on the absorption of light by complexes with different ligands.

Question 13

What is the hybridisation of [ CrF _6 ]^ 3- ?

Accepted Answer

The electronic configuration of Cr is [ Ar ] 3 d^5 4 s^1. [ CrF _6 ]^ 3- has d^2 s p^3-hybridisation and octahedral geometry.

Question 14

Match the species in Column I with their types in Column II. Codes

Accepted Answer

The correct match is A (4) ; B (3) ; C (2) ; D (1) A. DDT Pesticides B. NaClO _3 Herbicides C. Cl _2 Disinfectant D. PAN Photochemical smog

Question 15

Select the correct statement about the complex [ Co ( NH _3 )_5 SO _4 ] Br

Accepted Answer

Answer option index: 3

Question 16

Which one of the following coordination compounds is used to inhibit the growth of tumours?

Accepted Answer

Cisplatin [ Pt ( NH _ 3 )_ 2 Cl _ 2 ] is used in cancer treatment.

Question 17

[ Fe ( en )_ 2 ( H _ 2 O )_ 2 ]^ 2+ + en complex ( X ). The correct statement about the complex (X) is -

Accepted Answer

Complex X is [ Fe ( en )_ 3 right ]^ 2+ ; as 'en' is a strong field ligand pairing of electrons will take place. [ Fe ( en )_ 3 ]^ 2+ : d^ 2 s p^ 3 hybridisation Hence, hybridisation is d^ 2 s p^ 3 and complex is diamagnetic. As it has 3 bidentate symmetrical 'en' ligands so it will not show geometrical isomerism.

Question 18

The d -electron configurations of Cr ^ 2+ , Mn ^ 2+ , Fe ^ 2+ and Co ^ 2+ are d^ 4 , d^ 5 , d^ 6 and d^ 7 respectively. Which one of the following will exhibit the lowest paramagnetic behaviour? (Atom

Accepted Answer

Since Co ^ 2+ has lowest no. of unpaired electrons hence lowest paramagnetic behaviour is shown by [ Co ( H _ 2 O )_ 6 ]^ 2+

Coordination Compounds — Previous Year Questions & Solutions