Coordination compounds nrs 1
nrs 2
Coordination compounds Ligands and its classification Central metal atom oxidation state coordination number Ionisation and coordination sphere
WERNERS THEORY OF COORDINATION COMPOUNDS 1. METAL ATOM EXIBITS TWO TYPES OF VALENCIES. IONISABLE VALENCY (PRIMARY) NON IONISABLE VALENCY (SECANDARY) 2. SECANDARY VALENCY IS FIXED AND IS EQUAL TO CO ORDINATION NUMBER. 3. SECANDARY VALENCIES ARE DIRECTED TOWARDS FIXED POSSITION IN SPACE ARROUND METAL ION HENCE COMPLEX ION EXIBITS STEREO ISOMERISM nrs 4
ISOMERISM LINKAGE ISOMERISM Same formula and different properties STRUCTURAL Different bonds STEREO Different spatial arrangement IONISATION HYDRATE COORDINATION OPTICAL GEOMETRICAL
NOMENCLATURE In ionic complexes the cation is named first and then the anion. Neutral complexes are named in one word. In naming the co-ordination sphere the ligand are named first and followed by central metal ion.
Anionic ligands: Anionic ligands ending with ide are named by replacing e by o The ligands are named in an alphabetical order of preference. If there are several ligands of the same type [monodentate] are named using the prefix di, tri, tetra, penta etc. When the name of ligands include a numerical prefix then the term bis (2 ligands) tris (3 ligands), tetrakis (4 ligands) are used.
After naming all the ligands central metal ion is named. In case of cationic complex or neutral complex, the name of the metal is retained as such. In case of anionic complexes, the name of the metal is ended with ate, preferably selecting the Latin name of the metal. After naming the metals, its oxidation state is indicated in Roman numerals in parenthesis
Valence bond theory (VBT) Types of hybridization Shape 1. dsp 2 hybrdization Square planar 2. sp 3 hybridization Tetrahedron 3. d 2 sp 3 hybridization Octahedron
Crystal Field Theory Assumptions Ligands: negative point charges Metal-ligand bonding: entirely ionic strong-field (low-spin): large splitting of d orbitals weak-field (high-spin): small splitting of d orbitals
Crystal field splitting in octahedral coordination entities
Crystal field splitting in octahedral coordination entities
Crystal field splitting in octahedral coordination entities High spin Low spin
Complimentary colors and its wavelength
Complimentary colors and its wavelength
Crystal field splitting in octahedral coordination entities
Valence bond theory Reaction data Identification of formula Crystal field theory complex species CN and OS of central metal atom No. of unpaired d -electrons magnetic character and Calculation of magnetic moment
1. Which of the following pair contains complex salt and double salt respectively? a) FeSO 4, K 4 [Fe(CN) 6 ] b) [Cu(NH 3 ) 4 ]SO 4, FeSO 4.7H 2 O c) [Cu(NH 3 ) 4 ]SO 4, K 2 SO 4 Al 2 (SO 4 ) 3.24H 2 O d) MgSO 4 7H 2 O, CuSO 4
2. In the reaction Cu 2+ + 4NH 3 [Cu(NH 3 ) 4 ] 2+ (aq), Cu 2+ is acting as a(n) a) oxidizing agent b) Lewis acid c) solvent d) ligand
3. The number of moles of ions formed in 1M solution of Potassium hexacyanidoferrate(ii) would be a)2 b)3 c)4 d)5 K 4 Fe(CN) 6 4K + + 1 [Fe(CN) 6 ] 4- POTASSIUM FERROCYANIDE
4.which one of the following is a cationic complex compound? a)[ag(nh 3 ) 2 ]Cl b)[mn(cn) 6 ]K 4 c)[fe(cn) 6 ]K 4 d) K 3 [Fe(CN) 6 ] [Ag(NH 3 ) 2 ]Cl - [Ag(NH 3 ) 2 ] + + Cl -
5.What are the oxidation number (ON) and coordination number (CN) in the coordination compound, [Cu(en)(NH 3 ) 2 ]Cl 2? a) ON = 1, CN = 1 [Cu(en)(NH 3 ) 2 ]Cl 2 [Cu(en)(NH 3 ) 2 ] +2 + 2Cl - b) ON = 1, CN = 2 c) ON = 2, CN = 2 X + 0 (1) +(0 )(2) = +2 d) ON = 2, CN = 4 O S = X = +2 [Cu(en)(NH 3 ) 2 ]Cl 2 (ethylene diammine bidentate ligand + two monodentate ligands) CO. NO. = 2+2 = 4
6.In which of the following complexes the oxidation number of the central metal atom is zero? a) [Pt(NH 3 ) 2 Cl 2 ] b) [Cr(CO) 6 ] c) [Cr(NH 3 ) 3 Cl 3 ] d) [Cr(en) 2 Cl 2 ]
7.How many d- electrons are in the cobalt ion of K 3 [Co (CN) 6 ]? a)3 27 Co b) 5 c) 6 d) 4
PtCl 2 4NH 3 and CoCl 3 4NH 3 on treatment with excess of AgNO 3 solution gives two and one moles of AgCl precipitate respectively. The secondary valency of the metal ion in these complexes are respectively a)4 and 6 PtCl 2 4NH 3 2 AgCl - [Pt (NH 3 ) 4 ] Cl 2 b) 3and 6 c)6 and 4 CoCl 3 4NH 3 1 AgCl - [Co (NH 3 ) 4 Cl 2 ] Cl d)6 and 3 [Pt (NH 3 ) 4 ] Cl 2 [Co (NH 3 ) 4 Cl 2 ] Cl
9.Which of the following complex will give white precipitate with Barium chloride solution? a)[cr(nh 3 ) 5 SO 4 ]Cl b)[co(nh 3 ) 4 Cl 2 ]NO 2 c)[cr(nh 3 ) 5 Cl ]SO 4 d) K 4 [Fe (CN) 6 ]
10.Which of the following is non ionisable? a)[co(nh 3 ) 3 Cl 3 ] b)[co(nh 3 ) 4 Cl 2 ]Cl c)[co(nh 3 ) 5 Cl ]Cl 2 d)[co(nh 3 ) 6 ]Cl 2
11.In the test for nitrate in, the brown ring formed has a formula [Fe(H 2 O) 6 NO]SO 4. The oxidation number of iron in this complex is (a) + 1 (b) + 2 (c) + 3 (d) 0 [Fe(OH 2 ) 6 NO] SO 4 [Fe(OH 2 ) 6 NO] 2+ + SO 4 2- X(1)+6(0) + 1(0)=+2 hence x = +2
12.In the complex compound, [Co(NH 3 ) 6 ] [Cd Cl x ] the oxidation number of cobalt is + 3. The values of x is (a) 3 (b) 4 (c) 2 (d) 5 [Co(NH 3 ) 6 ] [Cd Cl 5 ] [Co(NH 3 ) 6 ] 3+ [Cd Cl x ] 3- +2(1) + x(-1)=-3 +2 x = -3 x = 5
IUPAC NAMENCLATURE
13.The formula of potassium trioxalatoaluminate(iii) is a)k 3 [Al(C 2 O 4 ) 3 ] b) K 2 [Al(C 2 O 4 ) 3 ] c) Al [K 3 (C 2 O 4 ) 3 ] K 3 [ Al (C 2O 4 ) 3 ] d) K[Al(C 2 O 4 ) 3 ]
14.Which name-formula combination is NOT correct? FORMULA NAME (I) [Co(NH 3 ) 4 (OH 2 )I]SO 4 tetraammineaquaiodidocobalt(iii) sulphate (II) K[Cr(NH 3 ) 2 Cl 4 ] potassium diamminetetrachloridochromate(iii) (III) [Mn(CN) 5 ] 2- pentacyanomanganate(ii) ion (IV) Ca[PtCl 4 ] calcium tetrachloridoplatinate(ii) a)i b)ii c)iii d) IV
15.The IUPAC name of [CoCl(NO 2 )(en) 2 ]Cl is a)chloridonitrito-nbis(ethylenediamine) cobaltic (III) chloride b)chloridonitrobis(ethylenediamine) cobalt (II) chloride c)chloridobis(ethylenediamine)nitrito-ncobalt (III) chloride d)bis(ethylenediamine)chloridonitro cobalt (III) chloride
16.The correct IUPAC name of K 2 [Zn(OH) 4 ] is a)potassium tetrahydroxy zinc (II) b)potassium tetrahydroxidozincate (II) c) Potassium tetrahydroxy zinc (0) d)potassium hydroxo zinc (II)
17.Lithium tetrahydrido Aluminate is correctly represented as a)al[lih 4 ] b)al 2 [LiH 4 ] 3 c)li[alh 4 ] d)li[alh 4 ] 2
18.The IUPAC name of the compound [Pt(NH 3 ) 3 Br(NO 2 )Cl] Cl is (a) Triamminebromidochloridonitrito-Nplatinum (IV) chloride (b) Triamminenitrochlorobromoplatinum (III) chloride (c) Triamminebromonitrochloroplatinum (IV) chloride (d) Triamminebromodichloronitroplatinum (IV)
ISOMERISM
19.The pentamminesulphatocobalt(iii) two compounds bromide Sulphatopentaminecobalt(III) bromide & pentaminechlorocobalt(iii) [Co(NH 3 ) 5 SO 4 ] Br sulphate, represents a)linkage isomerism pentamminechlorocobalt(iii) sulphate b)ionisation isomerism c)co-ordiantion compounds d)solvate isomerism [Co Cl (NH 3 ) 5 ] SO 4
20.The complex ions I.[Co(NH 3 ) 4 (NO 2 )Cl] + II. [Co(NH 3 ) 4 (ONO)Cl] + a)coordination isomers b)optical isomers c)linkage isomers. d)geometric isomers are:
21.Which kind of isomerism is exhibited by octahedral Co(NH 3 ) 4 Br 2 Cl a)geometrical and Ionization b)geometrical and Optical c)optical and Ionization d)geometrical only Co(NH 3 ) 4 Br 2 Cl [Co(NH 3 ) 4 Br 2 ]Cl [Co(NH 3 ) 4 Br Cl] Br M X 4 Y 2
22.Which one of the following complexes can exhibit geometrical isomerism? a)[pt(nh 3 ) 2 Cl 2 ] - (square planar) b)[zn(nh 3 ) 2 Cl 2 ] - (tetrahedral) c)[cu(nh 3 ) 4 ] 2+ - (square planar) d)[co(nh 3 ) 5 Cl] 2+ - (octahedral)
23.The spin magnetic moment of Cobalt in compound K [Co(SCN) 4 ] is a)3.87bm Co 1s 27 2 2s 2 2p 6 3s 2 3p 6 4s 2 3d 7 Oxidation state of Co in this complex is +3 b) 2.87BM Electronic configuration of Co +3 is c)4.89bm 1s 2 2s 2 2p 6 3s 2 3p 6 3d 6 with four unpaired d)5.92bm electrons. µ= n(n + 2)= 24 = 4.89 BM
[FeF 6 ] 3-26Fe 3+ 3d 5 5 WFL HIGH SPIN 24.Which of the following has highest magnetic moment? [Co (NH (a) [FeF 3 )] 3+ 6 ] 3-27Co 3+ 3d 6 4 SFL LOW SPIN (b) [Co (NH 3 )] 3+ [Fe(CN) 6 ] 4-26Fe 2+ 3d 6 4 SFL LOW SPIN (c) [Fe(CN) 6 ] 4- [Mn(CN) (d) [Mn(CN) 6 ] 4-25Mn 6 ] 4-2+ 3d 5 5 SFL LOW SPIN I - < F - OH -, ONO - < OH 2 < NCS - < NH 3 <NO - 2 < CN -, CO weak-field ligands strong-field ligands 5e 0e 0e 1e
[Ni(CO) 4 ] 28 Ni 0 3d 8 sp 3 SFL No pairing of e 25.Which of the following complexes is inner orbital complex? [Fe(CN) 6 ] 4-26Fe 2+ 3d 6 d 2 sp 3 SFL Pairing of e (a) [Ni(CO) 4 ] [Co(F) (b)[fe(cn) 6 ] 4-6 ] 3-27 Co 3+ 3d 6 sp 3 d 2 WFL No pairing of e (c) [CoF 6 ] 3- [Mn(F) (d) [MnF 6 ] 3-25Mn 2+ 3d 5 sp 3 d 2 WFL No pairing 6 ] 3- of e I - < F - OH -, ONO - < OH 2 < NCS - < NH 3 <NO - 2 < CN -, CO weak-field ligands strong-field ligands
26. The coordination complex, [Cu(OH 2 ) 6 ] 2+ has one unpaired electron. Which of the following statements are TRUE? 1)The complex is octahedral. TRUE 2) The complex is an outer orbital complex. 3) The complex is d 2 sp 3 hybridized. FALSE 4) The complex is diamagnetic. FALSE 5) The coordination number is 6. TRUE (a) 1, 4 (b) 1, 2, 5 (c) 2, 3, 5 (d) 2, 3 TRUE
27.Nickel Ni- 1s 28 2 (z=28) 2s 2 2p 6 combines 3s 2 3p 6 4swith 2 3d 8 a uninegative monodentate ligand X - to Oxidation state of Ni in this paramagnetic complex is +2 form a paramagnetic complex [NiX] 2-. Electronic configuration of Ni +2 is The number of unpaired electrons in 1s 2 2s 2 2p 6 3s 2 3p 6 3d 8 with two unpaired nickel and geometry of this complex ion electrons. are respectively a)one, tetrahedral c)one, square planar 3d 4s 4p b)two, tetrahedral d)two, square planar
28.The calculated spin magnetic moment of iron in compound K 4 [Fe(CN) 6 ] is (a)3.87bm 26 Fe- 1s 2 2s 2 2p 6 3s 2 3p 6 4s 2 3d 6 Oxidation b)2.87bm state of Fe in this complex is +2 Electronic c)4.89bm configuration of Fe +2 is d)5.92bm 1s 2 2s 2 2p 6 3s 2 3p 6 3d 6 with four unpaired electrons. µ= n(n + 2)= 24 = 4.89 BM
29.Which of the following system in octahedral complex has unpaired maximum electrons? (a) d 7 (high spin) WFL AND NO PAIRING (b) d 9 (high spin) (c) d 6 (low spin) (d) d 4 (low spin) WFL AND NO PAIRING SFL AND PAIRING SFL AND PAIRING
30.Which of the following compound is not coloured? (a) Na 2 [CuCl 4 ] (b) Na 2 [CdCl 4 ] (c) K 4 [Fe(CN) 6 ] (d) K 3 [Fe(CN) 6 ] METAL ION ELECTRONIC CONFIGURATION 29Cu 2+ [Ar] 3d 9 4s 0 48Cd 2+ [Ar] 3d 10 4s 0 26Fe 2+ [Ar] 3d 6 4s 0 26Fe 3+ [Ar] 3d 5 4s 0
31.In octahedral field of ligands, the d-subshell splits up into 2 set of orbitals, which are designated as (a)d 1 and d 2 (b) tg and e2g (c) e g and t 2g (d) fg and f2g
32.The crystal field splitting energy for octahedral complex ( 0 ) and tetrahedral complex ( t ) are related as (a) t = 4 / 9 o (b) t = 0.5 o (c) t = 9 / 4 o (d) t = 5 / 3 o
33.In which of the following octahedral complexes of Co (at no. 27), will the magnitude of Δ O be the highest? a)[co(c 2 O 4 ) 3 ] 3 b) [Co(H 2 O) 6 ] 3+ c)[co(nh 3 ) 6 ] 3+ d) [Co(CN) 6 ] 3
34.How many unpaired electrons are there in a strong field iron(ii) octahedral complex? a) Fe- 0 1s 26 2 2s 2 2p 6 3s 2 3p 6 4s 2 3d 6 Oxidation state of Fe in this complex is +2 b) 6 Electronic configuration of Fe +2 is c) 2 1s 2 2s 2 2p 6 3s 2 3p 6 3d 6 with four unpaired d) 4 electrons. In strong field pairing of e occurs
35.Strong field ligands such as CN - : a) usually produce high spin complexes and small crystal field splittings. b) usually produce low spin complexes and small crystal field splittings. c) usually produce low spin complexes and high crystal field splittings. d) usually produce high spin complexes and high crystal field splittings.
36.Based on the crystal-field strengths which Co(III) complex is most likely highspin? a) b) c) d) - - - F CH 2CN NH 3 NO 2 CN 3 [Co(NH 3) 6] 3 [Co(NO 2) 6] 3 [Co(CN) ] 3 [CoF 6] 6
37.In the process of extraction of gold, Roasted gold ore O2 CN H2O [X] OH Identify the complexes [X] and [Y] [X] Zn [Y] Au a)x = [ Au ( CN) 2 ] - and Y = [ Zn (CN) 4 ] 2- b) X = [ Au ( CN) 4 ] 3 - and Y = [ Zn (CN) 4 ] 2- c) X = [ Au ( CN) 2 ] - and Y = [ Zn (CN) 6 ] 4- d) X = [ Au ( CN) 4 ] - and Y = [ Zn (CN) 4 ] 2-
38.Co-ordination compounds have great importance in biological systems in this context, which of the following statements is incorrect? a)cyanocobal amine (vitamin B 12 ) contains cobalt b)haemoglobin contains iron c)chlrophyl contains calcium d)carboxypeptidase A contains zinc
39.Which of the following biomolecules contains non transition metal ion? a)vitamin B 12 b)chlorophyl c)haemoglobin d)insulin Zn Mg Co Fe
40. One mole of complex compound Co(NH 3 ) 5 Cl 3 gives 3 moles of ions on dissolution in water. One mole of the same complex reacts with 2 moles of AgNO 3 solution to give 2 moles of AgCl. The structure of complex is a)[co Co(NH (NH 3 ) 3 Cl Cl 3 ]2NH 3 b)[co (NH 3 5 4 Cl 2 ]NH 3 3 Cl [Co (NH ) Cl] 2+ + 2Cl - 3 5 c)[co (NH 3 ) 4 Cl]Cl 2 NH 3 d)[co (NH 3 ) 5 Cl]Cl 2-2AgCl [Co (NH 3 ) 5 Cl]Cl 2
41.An excess of AgNO 3 is added to 100 ml of a 0.01 M solution of dichlorotetraaquachromium(iii) chloride. The number of moles of AgCl precipitated would be a)0.001 b)0.002 c) 0.003 d) 0.01 [Cr (H 2 O) 4 Cl 2 ] Cl NO. of moles of Cl formed on dissociation is = 0.01/100 = 0.001
Which of the following best explains why coordination compounds containing Cu 2+ are colored but coordination compounds containing Cu + are not? a)the 3d orbitals in Cu + are completely empty so the transfer of an electron cannot occur. Cu b)the 29 3d + - 1s orbitals 2 2s in 2 2p Cu 2+ are 6 3s completely 2 3p 6 4s 3d filled 10 4s so the 0 transfer of an electron can occur. c)the 3d orbitals in Cu + are completely filled so the transfer of an Cu electron cannot occur. d)cu 29 +2-1s 2 2s 2 2p 6 3s 2 3p 6 4s 3d 9 4s 0 + absorbs all wavelengths of visible light which makes it appear colorless.
No. of unpaired electrons 42.The μ = 2.82 calculated BM means magnetic vanadium moment has two for μ = n (n+2)bm Vanadium unpaired electrons with an oxidation K n [V(ox) 3 ] complex compound Z = state is 23 of +3 3d 2.82 BM. What is the value of 2 n in 3d the 3 4s 2 0 0 formula? (ox 2 = oxalate ion) let the 1 charge on 3 the = 1.73 complex ion be X a) Then 2 2 X = 1(+3) 8 + = (-2) 2.823 =+ 3-6 =-3 b) To 1 balance 3 K -3 charge 15 = 3.87 put 3 K + 3 [ V ( OX) 3 ] ions c) Hence 3 n = 3 d) 4 4 24 = 4.89 5 35 = 5.91 K 3 [ V ( OX) 3 ]
K43. How many unpaired d- electrons 3 [Co(CN) 6 ] Oxidation are present state in the of cobalt central in metal this ion of complex K 3 [Co(CN) is 6 ]? +3 a) 3 Electronic b) 5 configuration of Co is 3d 7 4s 2 c) 4 Electronic d) 6 configuration of Co 3+ 3d 6
44.What is the oxidation number of chromium in [Cr(en) 2 (NH 3 ) 2 ]Cl 3? a)-3 b)+3 c)+2 d) -2 [Cr(en) 2 (NH 3 ) 2 ] Cl 3 [Cr(en) 2 (NH 3 ) 2 ] +3 + 3 Cl - X + 0 (2) +(0 )(2) = +3 X = +3
Co(H 45. One mole of complex compound Co(H 2 O) 5 Cl 3 2 O) 5 Cl 3 [Co Cl (H 2 O) 5 ] +2 + 2Cl gives 3 moles of ions on dissolution in water. ( 3 moles) One mole of the same complex reacts with 2 2AgNO moles of AgNO 3 solution to give 2 moles 3 of AgCl. The structure of complex is Co(H 2 O) 5 Cl 3 + 2AgNO 3 2 AgCl a)[co (H 2 O) 3 Cl 3 ].2H 2 O (2 moles) b)[co (H 2 O) 4 Cl 2 ]Cl.H 2 O c)[co (H 2 O) 4 Cl]Cl 2 H 2 O Formula d)[co Cl of (Hthe 2 O) complex 5 ]Cl is [Co Cl (H 2 O) 5 ] Cl 2 2
K 4 [Fe(CN) 6 ] CENTRAL 46. The METAL calculated ION IS spin Fe OS magnetic IS +2 ELECTRONIC CONFIGURATION OF IRON IS moment of iron in compound [Ar] 3d 6 4s 2 ELECTRONIC K 4 [Fe(CN) CONFIGURATION 6 ] is OF Fe 2+ IS [Ar] 3d 6 a) 3.87BM b) 2.87BM CONTAINS 4 UNPAIRED ELECTRONS. c) 4.89BM µ= n(n + 2)= 24 = 4.89 BM d) 5.92BM
0.02 [Co SO mole of [ Co ( NH ) SO ] and 4 (NH 3 ) 5 ]Br [Co Br (NH 3 5 4 3 ) 5 ] SO 4 0.02 (0.02 mole mole)/2l of [ Co( NH3 ) 5Br] SO(0.02 was mole)/2l 4 mixed and made up to 2L by adding water. = 0.01mol/L = 0.01mol/L 1 litre of above mixture + excess AgNO 3 Y 1 litre of above mixture + excess BaCl 2 Z Number 1 litre of of above moles of Y and Z are 1 litre of above mixture +excess a)0.01 & 0.01 AgNO b)0.02 3 0.01 mol/l & 0.01 of AgBr (Y) c)0.01 & 0.02 d)0.02 & 0.02 mixture +excess BaCl 2 0.01 mol/l of BaSO 4 (Z)
Excess of silver nitrate solution is added to 100 ml of 0.01 M Pentaaquachloridochromium(III) chloride solution. The mass of silver chloride obtained in grams is [Atomic mass of silver is 108]. a)287 10 3 b)143.5 10 3 [Co(H 2 O) 5 Cl]Cl 2 [Cl] = 2 x 0.01 = 0.02M c)143.5 10 2 d) 2.87 [AgCl] = 0.02 Mass of AgCl = 0.02 x (108 +35.5) = 2.87
MCI 3.5H 2 O In the complex MCI 3.5H 2 O, the co-ordination number of the metal M is six and there is no molecule of hydration. Then the volume of 0.1 M AgNO 3 solution needed to precipitate the free chloride ions in 200 ml of 0.01 M solution CI 3 of the complex is [M(H 2 O) 5 CI ] CI 2 200 ml of 0.01 M solution contains 200ml of 0.02 molar chloride ions. M 1 V 1 = M 2 V 2 0.02 X 200 = 0.1 X V 2 V 2 = 40mL (a) 80 ml (b) 40 ml (c) 20 ml (d) 120 ml
47. which one among the following show magnetic moment of 1.73 BM? a)[cu(nh 3 ) 4 ] 2+ b)[ni(cn) 4 ] 2 c) TiCl 4 d) [CoCl 6 ] 3 Cu 2+ 3d 9 1e Ni 2+ 3d 8 2e Ti 4+ 3d 0 0e Co 3+ 3d 6 4e
Which among the following represent chelating ligand? a) SCN - b) CN - c) 2, 2-Dipyridyl d) OH -