124 + Interview Questions in Coordination Compounds in Chemistry

1.	The donation of lone pair of electrons of CO carbon into the vacant orbital of metal atom results in _________ bond.(a) sigma(b) pi(c) back(d) synergicI had been asked this question by my school principal while I was bunking the class.I would like to ask this question from Bonding in Metal Carbonyls in portion Coordination Compounds of Chemistry – Class 12
Answer» RIGHT choice is (a) SIGMA The EXPLANATION is: Synergic BONDING is the OVERALL effect of the sigma and pi interactions in metal carbonyl bonds. M-C pi bonds are also known as back bonding.

Discussion

2.	Which reagent is used for detecting Ni^2+ ions in solution?(a) EDTA(b) Dimethylglyoxime(c) α-nitroso-β-naphthol(d) CupronThe question was asked in an interview for internship.My question is based upon Coordination Compounds Importance and Applications topic in portion Coordination Compounds of Chemistry – Class 12
Answer» CORRECT answer is (B) Dimethylglyoxime The explanation: When dimethylglyoxime is added to a solution along with AMMONIUM hydroxide, the formation of a bright red precipitate indicates the presence of Ni^2+ ions in solution. This is DUE to the formation of nickel dimethylglyoxime complex.

Discussion

3.	The degree of ________ between the metal ion and the ligand directly influences the stability of the complex in solution.(a) association(b) dissociation(c) ionisation(d) freedomThis question was addressed to me in an interview for job.My question comes from Stability of Coordination Compounds in division Coordination Compounds of Chemistry – Class 12
Answer» CORRECT option is (a) association To explain I would say: The magnitude of the equilibrium constant for the association quantitatively EXPRESSES the STABILITY of the COMPLEX in SOLUTION.

Discussion

4.	The platinum complex, trans-platin has been used in cancer treatment.(a) True(b) FalseThe question was asked in a national level competition.My question is based upon Coordination Compounds Importance and Applications topic in portion Coordination Compounds of Chemistry – Class 12
Answer» Right option is (B) False Easy explanation: Cis-platin is a coordination COMPLEX of platinum which is EFFECTIVE in inhibiting the GROWTH of tumours.

Discussion

5.	Hardness of water is estimated by simple titration with which compound?(a) Na2(EDTA)(b) Fe(EDTA)(c) Mg(EDTA)(d) Co(EDTA)The question was posed to me by my college director while I was bunking the class.This interesting question is from Coordination Compounds Importance and Applications topic in section Coordination Compounds of Chemistry – Class 12
Answer» The correct answer is (a) Na2(EDTA) The best explanation: The Ca^2+ and MG^2+ ions form stable complexes with EDTA, and the difference in the stability CONSTANTS of Ca and Mg complexes helps in the estimation of HARDNESS of WATER.

Discussion

6.	How are the stepwise stability constants (K) related to the overall stability constant (β)?(a) βn = K1 + K2 + …. + Kn(b) βn = K1 x K2 x … x Kn(c) βn = logK1 + logK2 + …. + logKn(d) βn = 1/(K1 + K2 + …. + Kn)This question was posed to me in a national level competition.My doubt stems from Stability of Coordination Compounds in chapter Coordination Compounds of Chemistry – Class 12
Answer» Correct ANSWER is (b) βn = K1 x K2 x … x Kn Easiest explanation: The overall stability CONSTANT is the PRODUCT of all the stepwise stability constants of each individual reaction.

Discussion

7.	Which of the following biologically important coordination compounds has a magnesium central atom?(a) Chlorophyll(b) Haemoglobin(c) Vitamin B12(d) Carboxypeptidase-AI got this question during an interview for a job.The above asked question is from Coordination Compounds Importance and Applications topic in division Coordination Compounds of Chemistry – Class 12
Answer» The correct CHOICE is (a) Chlorophyll Best EXPLANATION: Chlorophyll is the green PIGMENT in plants, responsible for photosynthesis, is a coordination compound of MG.

Discussion

8.	Identify the correct relation between Δo and Δt, where Δo denotes crystal field splitting in octahedral complexes and Δt denotes crystal field splitting in tetrahedral complexes.(a) Δo < Δt(b) Δo > Δt(c) Δo = Δt(d) Δo ≥ ΔtThe question was posed to me in examination.My question is based upon Bonding in Coordination Compounds topic in division Coordination Compounds of Chemistry – Class 12
Answer» Correct ANSWER is (b) Δo > Δt The explanation: It has been OBSERVED that splitting energy in tetrahedral fields is CONSIDERABLY LESS than in octahedral complexes. To be precise, it has been found that Δt = (4/9) Δo.

Discussion

9.	As the crystal field splitting energy in octahedral field increases, the wavelength of light absorbed _________(a) Increases(b) Decreases(c) Remains the same(d) May increase or decreaseThis question was addressed to me in quiz.The above asked question is from Bonding in Coordination Compounds topic in portion Coordination Compounds of Chemistry – Class 12
Answer» Right answer is (B) Decreases Best explanation: If Δo is less (as in weak field LIGANDS), the EXCITATION energy will be the SMALLEST and the largest WAVELENGTH will be absorbed. On the other hand, Δo is high (as in strong field ligands), the excitation energy will be the largest and the smallest wavelength will be absorbed.

Discussion

10.	Which of the following ligands is most likely to form high spin complexes in octahedral fields?(a) Cl^–(b) OH^–(c) C2O4^–(d) CN^–This question was posed to me in exam.My question is taken from Bonding in Coordination Compounds in chapter Coordination Compounds of Chemistry – Class 12
Answer» Right option is (a) CL^– To elaborate: Cl- is the WEAKEST field ligand in the given options. The splitting field Δo is small and the energy separation between the eg and t2g ORBITALS are narrower. Hence, the electrons TEND to OCCUPY the eg orbitals easily and are likely to have a greater number of half-filled orbitals.

Discussion

11.	What will be the electronic configuration of d^5 in terms of t2g and eg in an octahedral field when Δo
Answer» Right answer is (c) t2g^3 eg^2 Best EXPLANATION: When the field splitting is less than the pairing energy, the energy gap between the two sets of d orbitals is SMALL. This allows the electrons to occupy the higher energy orbitals once the LOWER orbitals are singly occupied. Thus, the configuration will be t2g^3 eg^2, with one ELECTRON in each ORBITAL.

Discussion

12.	The following structure of a carbonyl compound is formed by which transition metal.(a) Ni(b) Cr(c) Mn(d) CoThe question was asked in my homework.My question is based upon Bonding in Metal Carbonyls in section Coordination Compounds of Chemistry – Class 12
Answer» The correct answer is (d) Co Best EXPLANATION: There are 8 CARBONYL ligands present. This COMPOUND is formed by cobalt METAL ion an is named octacarbonyldicobalt(0). It also has Co-Co BOND bridged by two carbonyl groups.

Discussion

13.	By how much percentage does the energy of eg orbitals increase by from the average field splitting energy in octahedral complexes?(a) 40%(b) 45%(c) 50%(d) 60%The question was asked in a national level competition.I would like to ask this question from Bonding in Coordination Compounds topic in division Coordination Compounds of Chemistry – Class 12
Answer» RIGHT option is (d) 60% The best EXPLANATION: The ENERGY of the TWO eg orbitals will increase by (3/5)Δo, that is 60% of the AVERAGE energy that separates the field in octahedral complexes.

Discussion

14.	If β is the formation constant, then the instability constant = ________(a) 1 – β(b) β – 1(c) (1/β)(d) log(β)This question was posed to me in exam.My question is based upon Stability of Coordination Compounds in section Coordination Compounds of Chemistry – Class 12
Answer» The correct option is (c) (1/β) EXPLANATION: The INSTABILITY CONSTANT is ALSO known as the dissociation constant. It is defined as the reciprocal of the FORMATION or stability constant.

Discussion

15.	Which of the following orbitals does not belong to t2g orbitals?(a) dxy(b) dyz(c) dxz(d) dz^2I have been asked this question in exam.My question is from Bonding in Coordination Compounds in chapter Coordination Compounds of Chemistry – Class 12
Answer» The correct choice is (d) dz^2 Easiest explanation: t2g is a set of three d orbitals of lower energy in OCTAHEDRAL COMPLEXES. The two REMAINING d orbitals of higher energy FORM the eg set.

Discussion

16.	The complex [Co(H2O)6]^3+ absorbs the wavelength of light corresponding to orange colour. Predict the colour of the coordination compound based on this information.(a) Red(b) Yellow(c) Blue(d) ColourlessThis question was posed to me by my school principal while I was bunking the class.The question is from Bonding in Coordination Compounds in chapter Coordination Compounds of Chemistry – Class 12
Answer» CORRECT option is (c) Blue Easy explanation: This is because of the concept of COMPLEMENTARY COLOURS. The colour of the complex is complementary to that which is absorbed and is generated from the WAVELENGTH that is left over.

Discussion

17.	Haemoglobin is a complex compound of which metal ion?(a) Fe^2+(b) Fe^3+(c) Co^2+(d) Co^3+The question was asked in semester exam.I'm obligated to ask this question of Coordination Compounds Importance and Applications in section Coordination Compounds of Chemistry – Class 12
Answer» The CORRECT choice is (a) Fe^2+ For explanation I would say: Haemoglobin is the red pigment of blood which acts as the oxygen CARRIER and it a coordination compound of IRON(II).

Discussion

18.	Tetrahedral fields can easily form low spin complexes.(a) True(b) FalseThe question was posed to me during an interview.My doubt stems from Bonding in Coordination Compounds topic in division Coordination Compounds of Chemistry – Class 12
Answer» Right choice is (b) False Easy explanation: The splitting energy in tetrahedral fields is almost half of that of octahedral fields. Due to this, the orbital splitting ENERGIES are not very large, which makes it difficult for ELECTRON pairing and THEREFORE LOW spin complexes are RARELY formed.

Discussion

19.	If the values of stepwise stability constants for a series of successive reactions are logK1 = 4, logK2 = 3.2, logK3 = 2.7 and logK4 = 2, what is the value of β4?(a) 11.9(b) 7.94 x 10^11(c) 1.47 x 10^5(d) 27.4I got this question in unit test.This interesting question is from Stability of Coordination Compounds in division Coordination Compounds of Chemistry – Class 12
Answer» Correct choice is (b) 7.94 X 10^11 To explain: logβ4 = logK1 + LOGK2 + logK3 + logK4 \(\Rightarrow\)log10β4 = 4 + 3.2 + 2.7 + 2 = 11.9 \(\Rightarrow\)β4 = antilog(11.9) \(\Rightarrow\)β4 = 7.94 x 10^11

Discussion

20.	The complex ion [Ag(S2O3)2]^3- is associated with which field?(a) Electroplating(b) Medicine(c) Water treatment(d) PhotographyI had been asked this question during an internship interview.My enquiry is from Coordination Compounds Importance and Applications topic in section Coordination Compounds of Chemistry – Class 12
Answer» Right OPTION is (d) Photography For explanation I WOULD say: In black and white photography, the FILM is fixed by WASHING with hypo solution which dissolves the undecomposed silver bromide to FORM [Ag(S2O3)2]^3-.

Discussion

21.	Two complexes A and B have dissociation constants 1.0 x 10^-12 and 4.7 x 10^-14 respectively. Which complex will be more stable?(a) A(b) B(c) Both are equally stable(d) Cannot be determinedThe question was asked in an interview for internship.This intriguing question originated from Stability of Coordination Compounds in chapter Coordination Compounds of Chemistry – Class 12
Answer» The CORRECT OPTION is (b) B The EXPLANATION: The smaller the value of dissociation constant, more STABLE the COMPLEX will be in solution. Since 4.7 x 10^-14 < 1.0 x 10^-12, complex B is more stable.

Discussion

22.	Identify the correct order of increasing field strength of the ligands.(a) SCN^–, NH3, NCS^–, CN^–(b) NCS^–, SCN^–, NH3, CN^–(c) SCN^–, NCS^–, NH3, CN^–(d) NCS^–, NH3, SCN^–, CN^–I have been asked this question by my school principal while I was bunking the class.The doubt is from Bonding in Coordination Compounds in portion Coordination Compounds of Chemistry – Class 12
Answer» Correct answer is (c) SCN^–, NCS^–, NH3, CN^– For explanation: ACCORDING to the SPECTROCHEMICAL series, thiocyanate is WEAKER than isothiocyanate which is in TURN weaker than amine and CYANIDE ligands.

Discussion

23.	The metal-carbon bond in metal carbonyls possesses only sigma character.(a) True(b) FalseThis question was addressed to me by my college professor while I was bunking the class.This question is from Bonding in Metal Carbonyls in chapter Coordination Compounds of Chemistry – Class 12
Answer» Correct choice is (b) False Best explanation: The M-C BOND in metal CARBONYLS has both sigma and pi BONDS and this helps in creating a synergic EFFECT and, hence strengthening the bond.

Discussion

24.	For a particular complex, the dissociation equilibrium constant is given as 2.3 x 10^-9. What will be the overall stability constant for this complex?(a) 4.35 x 10^-10(b) 4.35 x 10^10(c) 4.35 x 10^-8(d) 4.35 x 10^8I got this question during a job interview.My enquiry is from Stability of Coordination Compounds topic in section Coordination Compounds of Chemistry – Class 12
Answer» Right choice is (d) 4.35 X 10^8 For explanation I would SAY: Formation CONSTANT = 1/(dissociation constant) \(\Rightarrow\)β = 1/(2.3 x 10^-9) \(\Rightarrow\)β = 4.35 x 10^8

Discussion

25.	The coordination complex chloridotris (triphenylphosphine) rhodium(I) is used in the hydrogenation of alkenes. It is also known as __________ catalyst.(a) Grubb(b) Pearlman(c) Wilkinson(d) Ziegler-NattaI have been asked this question during an interview for a job.My doubt is from Coordination Compounds Importance and Applications in division Coordination Compounds of Chemistry – Class 12
Answer» RIGHT choice is (C) Wilkinson To elaborate: Coordination compounds may be used as homogeneous or heterogeneous catalysts for MANY reactions. Wilkinson CATALYST is used as a homogeneous catalyst in hydrogenation of ALKENES, whereas Ziegler¬-Natta catalyst is used as a heterogeneous catalyst for the polymerisation of olefins.

Discussion

26.	What is the geometry of pentacarbonyliron(0)?(a) Square planar(b) Tetrahedral(c) Trigonal bipyramidal(d) OctahedralThis question was addressed to me in examination.This intriguing question originated from Bonding in Metal Carbonyls in chapter Coordination Compounds of Chemistry – Class 12
Answer» The CORRECT OPTION is (C) Trigonal bipyramidal The explanation is: The COORDINATION NUMBER of pentacarbonyliron(0) is 5 as CO is a unidentate ligand and hence its geometry id trigonal bipyramidal.

Discussion

27.	Given below is the incomplete equation for the extraction process of gold using potassium cyanide. Identify the missing reagent.(a) Water(b) Oxygen(c) Water + air(d) Zinc dustI have been asked this question in an interview for internship.The origin of the question is Coordination Compounds Importance and Applications in section Coordination Compounds of Chemistry – Class 12
Answer» Correct answer is (c) Water + air The EXPLANATION is: Gold COMBINES with cyanide in the PRESENCE of air and water to form [Au(CN)2]^– in aqueous solution. This is then TREATED with zinc dust to obtain gold in metallic form.

Discussion

28.	Observe the orbital splitting diagram of a tetrahedral field and find the value of x.(a) 0.178(b) 0.267(c) 0.4(d) 0.44The question was asked in an internship interview.My question is taken from Bonding in Coordination Compounds topic in chapter Coordination Compounds of Chemistry – Class 12
Answer» Right OPTION is (a) 0.178 Explanation: The value of x is ASKED in TERMS of Δo and not Δt. The t2 orbitals is at an energy of (2/5) Δt above the average energy. This is equal to (2/5) times (4/9) Δo = 0.178Δo.

Discussion

29.	Identify the correct order of decreasing field strength of the neutral ligands.(a) CO, en, NH3, H2O(b) CO, en, H2O, NH3(c) en, CO, NH3, H2O(d) en, CO, H2O, NH3I got this question in a national level competition.This key question is from Bonding in Coordination Compounds in section Coordination Compounds of Chemistry – Class 12
Answer» The correct option is (a) CO, en, NH3, H2O For explanation I would say: According to the spectrochemical series, CO is the strongest LIGAND. The ligands en, AMINE and WATER are weaker than CO and their FIELD strength decreases in that ORDER.

Discussion

30.	Hexaaquatitanium(III) chloride is a coloured compound that loses its colour on heating.(a) True(b) FalseThe question was asked during an interview for a job.My question is from Bonding in Coordination Compounds topic in portion Coordination Compounds of Chemistry – Class 12
Answer» The CORRECT option is (a) True For explanation I would SAY: Heating the compound removes the water which is the ligand. In the absence of a ligand, CRYSTAL field SPLITTING does not occur and hence the compound becomes colourless.

Discussion

31.	How is the M-C pi bond formed?(a) Donation of electron pair of half-filled metal d orbital to empty bonding pi orbital of CO(b) Donation of electron pair of filled metal d orbital to empty bonding pi orbital of CO(c) Donation of electron pair of filled metal d orbital to empty antibonding pi orbital of CO(d) Donation of electron pair of half-filled metal d orbital to empty antibonding pi orbital of COThe question was asked in exam.This question is from Bonding in Metal Carbonyls in portion Coordination Compounds of Chemistry – Class 12
Answer» Correct ANSWER is (C) DONATION of electron pair of filled metal d orbital to empty antibonding pi orbital of CO For explanation I would say: The pi bond involves donation of ELECTRONS from filled metal d ORBITALS into empty antibonding pi orbitals of CO. This is also called a back bond.

Discussion

32.	Which of the following ligands will be listed last in a coordination sphere?(a) Cl(b) CO(c) CO3(d) C2O4I have been asked this question in an internship interview.This intriguing question comes from Nomenclature of Coordination Compounds topic in division Coordination Compounds of Chemistry – Class 12
Answer» The correct choice is (d) C2O4 For explanation I would say: The ligands given are chlorine (Cl), carbonyl (CO), carbonate (CO3) and oxalate (C2O4). Of these, the ONE that OCCURS LAST in alphabetic ORDER is oxalate, and HENCE is will be listed at the end of the coordination entity.

Discussion

33.	Identify the correct naming for [Zn(OH)4]^2-.(a) Zinc tetrahydroxide(b) Tetrahydroxozincate(II)(c) Tetrahydroxidozincate(II)(d) Tetrahydroxylzincate(II)This question was addressed to me in an interview.The question is from Nomenclature of Coordination Compounds topic in section Coordination Compounds of Chemistry – Class 12
Answer» The CORRECT answer is (c) Tetrahydroxidozincate(II) The BEST explanation: The ligand OH is a negative group and should END with -o. The correct name for the OH group is hydroxide and the metal is mentioned after the LIGANDS.

Discussion

34.	Which of the following is the correct formulation of the entity according to IUPAC?(a) (Co(CN)6)^3-(b) [Co(CN)6]^3-(c) [Co (CN)6]^3-(d) [Co(CN)6]^-3This question was addressed to me in an interview for internship.Query is from Nomenclature of Coordination Compounds topic in chapter Coordination Compounds of Chemistry – Class 12
Answer» The correct answer is (b) [Co(CN)6]^3- The best explanation: The FORMULA of the coordination ENTITY should be enclosed within SQUARE brackets and there should be no space between the ligand and central metal. The number is written before the sign while INDICATION the CHARGE of the complex ion.

Discussion

35.	The SCN^– ion is a unidentate ligand.(a) True(b) FalseI got this question by my college professor while I was bunking the class.Query is from Definitions topic in portion Coordination Compounds of Chemistry – Class 12
Answer» Right answer is (a) True The explanation: SCN^– is an AMBIDENTATE ligand that can EITHER bond through S ATOM or N atom to a central atom/ion. But, at a time there is only a SINGLE donor atom, either S or N, making it a unidentate ligand. For a FACT, all ambidentate ligands are unidentate.

Discussion

36.	Identify the correct geometry and magnetic behaviour of the complex from the configuration shown.(a) Square planar, diamagnetic(b) Square planar, paramagnetic(c) Tetrahedral, diamagnetic(d) Tetrahedral, paramagneticThis question was posed to me in semester exam.This intriguing question comes from Bonding in Coordination Compounds topic in section Coordination Compounds of Chemistry – Class 12
Answer» Right option is (a) Square PLANAR, diamagnetic Easiest explanation: The HYBRIDISATION type of the complex is dsp^2 which CORRESPONDS to square planar GEOMETRY. Because there are no unpaired electrons, it is diamagnetic.

Discussion

37.	Optical isomers are also known as __________(a) structural isomers(b) facial isomers(c) meridional isomers(d) enantiomersThis question was posed to me in homework.This interesting question is from Isomerism in Coordination Compounds topic in section Coordination Compounds of Chemistry – Class 12
Answer» The correct choice is (d) enantiomers To EXPLAIN: OPTICAL isomers are different forms of the same complex that are MIRROR images of each other, and which cannot be SUPERIMPOSED. They are chiral complexes also known as enantiomers.

Discussion

38.	Which of the following compounds has a meridional isomer?(a) [Fe(NO)5Br]^+(b) [Al(CO)3(NO2)3](c) [K(NH)3)4(NO)2]^+(d) [Fe(H2O)2(CO)2(NO)2]^3+The question was posed to me in quiz.The query is from Isomerism in Coordination Compounds topic in division Coordination Compounds of Chemistry – Class 12
Answer» RIGHT answer is (B) [Al(CO)3(NO2)3] The best I can EXPLAIN: Fac-mer isomerism is only exhibited in octahedral coordination ENTITIES of the type [MA3B3] depending on the positions of the similar LIGANDS.

Discussion

39.	Which of the following is not a subdivision of structural isomerism?(a) Geometrical isomerism(b) Linkage isomerism(c) Coordination isomerism(d) Ionisation isomerismThe question was asked in quiz.The doubt is from Isomerism in Coordination Compounds topic in chapter Coordination Compounds of Chemistry – Class 12
Answer» Correct CHOICE is (a) GEOMETRICAL isomerism To EXPLAIN I would say: Geometrical isomerism is a TYPE of stereoisomerism. Linkage, coordination and ionisation isomers show structural isomerism with different bonds.

Discussion

40.	How many donor atoms can EDTA^4- ligand bind through?(a) 2(b) 4(c) 6(d) 8This question was addressed to me by my college director while I was bunking the class.This question is from Definitions in portion Coordination Compounds of Chemistry – Class 12
Answer» Correct CHOICE is (c) 6 Explanation: EDTA^4- is a hexadentate ligand which can bind through two NITROGEN and four oxygen atoms to a CENTRAL metal ION, giving it a total of 2 + 4 = 6 donor atoms.

Discussion

41.	The oxidation number of the central metal in a coordination entity is always a positive quantity.(a) True(b) FalseThis question was addressed to me in a job interview.My doubt stems from Definitions topic in section Coordination Compounds of Chemistry – Class 12
Answer» RIGHT choice is (b) False The best I can explain: The oxidation number might not ALWAYS be positive. It can also be 0 or a negative value. For example, the oxidation number of COBALT in K[Co(CO)4] is -1.

Discussion

42.	The coordination polyhedron geometry shown belongs to which of the following complexes?(a) [Co(NH3)6]^3+(b) [Ni(CO)4](c) [CoCl2(en)2]^2+(d) [Fe(C2O4)3]^3-This question was posed to me during an internship interview.My question is taken from Definitions topic in chapter Coordination Compounds of Chemistry – Class 12
Answer» Correct option is (B) [Ni(CO)4] Easiest explanation: The ARRANGEMENT shown is tetrahedral and CN=4. [Co(NH3)6]^3+ is octahedral with CN=6. Both [CoCl2(en)2]^2+ and [Fe(C2O4)3]^3- have didentate LIGANDS and hence CN=6.

Discussion

43.	Identify the Lewis acid in K3[Al(C2O4)3].(a) K^+(b) Al(c) Al^3+(d) [Al(C2O4)3]^3-This question was posed to me in final exam.I need to ask this question from Definitions in division Coordination Compounds of Chemistry – Class 12
Answer» The correct choice is (c) Al^3+ Explanation: ALUMINIUM ION is the LEWIS acid as it can accept 3 electrons from the donor ATOM to FORM the complex [Al(C2O4)3]^3-.

Discussion

44.	Which of the following is the coordination entity in K2[Zn(OH)4]?(a) K^+(b) Zn^2+(c) OH^–(d) [Zn(OH)4]^2-This question was addressed to me during an internship interview.My query is from Definitions topic in portion Coordination Compounds of Chemistry – Class 12
Answer» The correct OPTION is (d) [Zn(OH)4]^2- To EXPLAIN I would say: A COORDINATION entity consists of a central metal atom bonded to a fixed number of atoms/molecules. Here, K^+ is the counter ION, OH is the molecule bonded to the central atom which is Zn.

Discussion

45.	What is the sum of the oxidation number of cobalt in [Co(H2O)(CN)(en)2]^2+and [CoBr2(en)2]^+?(a) +3(b) +4(c) +5(d) +6The question was posed to me in unit test.My doubt is from Werner’s Theory of Coordination Compounds topic in portion Coordination Compounds of Chemistry – Class 12
Answer» The correct option is (d) +6 Best EXPLANATION: In [Co(H2O)(CN)(EN)2]^2+, the overall charge is +2 and 0, -1 and 0 on H2O, CN and en groups respectively. If ‘x’ is the oxidation number of Co, then (x + 0 – 1 + 0 = +2), which implies x=+3. Similarly, in [CoBr2(en)2]^+, the charge on Br is -1, so if ‘y’ is the oxidation number of Co, then (y – 2 + 0 = +1), which implies y=+3. Therefore, the SUM of the oxidation NUMBERS is 3 + 3 = 6.

Discussion

46.	Werner postulated that octahedral, tetrahedral and square planar geometrical shapes are more common in coordination compounds of ________(a) alkali metals(b) lanthanides(c) actinides(d) transition metalsI had been asked this question in an online quiz.My enquiry is from Werner’s Theory of Coordination Compounds in chapter Coordination Compounds of Chemistry – Class 12
Answer» Right option is (d) transition METALS The explanation: Transition metals BOND a bit differently from main group elements. They form coordinate covalent bonds and are often the central metal ion/atom of coordination complexes. Thus, OCTAHEDRAL, tetrahedral and SQUARE planar shapes are more common in transition metal central atoms.

Discussion

47.	The coordination entity [CrCl2(ox)2]^3- is optically active.(a) True(b) FalseI had been asked this question in my homework.My doubt stems from Isomerism in Coordination Compounds topic in section Coordination Compounds of Chemistry – Class 12
Answer» The correct ANSWER is (b) False The best EXPLANATION: [CrCl2(ox)2]^3- has two GEOMETRIC ISOMERS, cis and trans. The trans isomer is achiral and only the cis isomer is optically active. THUS, the statement is not always true.

Discussion

48.	Which statement regarding [Cr(NH3)6]^3+ is incorrect?(a) It has octahedral geometry(b) It has d^2sp^3 hybridisation(c) It is diamagnetic(d) It is a low spin complexI had been asked this question by my school teacher while I was bunking the class.This intriguing question originated from Bonding in Coordination Compounds topic in portion Coordination Compounds of Chemistry – Class 12
Answer» The correct answer is (c) It is diamagnetic Easiest explanation: Cr^3+ has six EMPTY orbitals- TWO 3d, one 4s and three 4p orbitals, which are OCCUPIED by six electron pairs from six NH3 molecules to form six d^2sp^3 hybridised orbitals. This leaves, three unpaired 3d electrons, making it paramagnetic. ALSO, since the inner d orbitals are involved, it is a low SPIN complex.

Discussion

49.	Identify the coordination isomer of [Fe(CO)4][Zn(CN)4].(a) Tetracyanidozinc(II) tetracarbonylferrate(II)(b) Tetracarbonylzinc(II) tetracyanidoferrate(II)(c) Tetracyanidoiron(II) tetracarbonylzincate(II)(d) Tetracarbonyliron(II) tetracyanidozincate(II)The question was asked in an interview for job.I want to ask this question from Isomerism in Coordination Compounds in section Coordination Compounds of Chemistry – Class 12
Answer» Correct option is (b) Tetracarbonylzinc(II) tetracyanidoferrate(II) Explanation: The coordination ISOMER will be [Zn(CO)4][Fe(CN)4] by interchanging the central atoms between the TWO complexes with [Zn(CO)4]^2+ being the cationic complex and [Fe(CN)4]^2- being anionic. The naming will be tetracarbonylzinc(II) tetracyanidoferrate(II).

Discussion

50.	Which of the following cannot be a ligand?(a) Ni^2+(b) Cl^–(c) H2O(d) NH3I got this question in a national level competition.My doubt stems from Definitions in section Coordination Compounds of Chemistry – Class 12
Answer» The correct choice is (a) Ni^2+ The explanation is: The ions/molecules BOUND to the central atom/ion is called a ligand. Ni^2+ is a metal ion, and according to WERNER the secondary valences can be satisfied only by NEUTRAL molecules or negative ions. Cl^–, H2O and NH3 are all possible ligands.

Discussion

Explore topic-wise InterviewSolutions in .

The platinum complex, trans-platin has been used in cancer treatment.(a) True(b) FalseThe question was asked in a national level competition.My question is based upon Coordination Compounds Importance and Applications topic in portion Coordination Compounds of Chemistry – Class 12

Which of the following ligands is most likely to form high spin complexes in octahedral fields?(a) Cl^–(b) OH^–(c) C2O4^–(d) CN^–This question was posed to me in exam.My question is taken from Bonding in Coordination Compounds in chapter Coordination Compounds of Chemistry – Class 12

What will be the electronic configuration of d^5 in terms of t2g and eg in an octahedral field when Δo

The following structure of a carbonyl compound is formed by which transition metal.(a) Ni(b) Cr(c) Mn(d) CoThe question was asked in my homework.My question is based upon Bonding in Metal Carbonyls in section Coordination Compounds of Chemistry – Class 12

If β is the formation constant, then the instability constant = ________(a) 1 – β(b) β – 1(c) (1/β)(d) log(β)This question was posed to me in exam.My question is based upon Stability of Coordination Compounds in section Coordination Compounds of Chemistry – Class 12

Which of the following orbitals does not belong to t2g orbitals?(a) dxy(b) dyz(c) dxz(d) dz^2I have been asked this question in exam.My question is from Bonding in Coordination Compounds in chapter Coordination Compounds of Chemistry – Class 12

Haemoglobin is a complex compound of which metal ion?(a) Fe^2+(b) Fe^3+(c) Co^2+(d) Co^3+The question was asked in semester exam.I'm obligated to ask this question of Coordination Compounds Importance and Applications in section Coordination Compounds of Chemistry – Class 12

Tetrahedral fields can easily form low spin complexes.(a) True(b) FalseThe question was posed to me during an interview.My doubt stems from Bonding in Coordination Compounds topic in division Coordination Compounds of Chemistry – Class 12

The metal-carbon bond in metal carbonyls possesses only sigma character.(a) True(b) FalseThis question was addressed to me by my college professor while I was bunking the class.This question is from Bonding in Metal Carbonyls in chapter Coordination Compounds of Chemistry – Class 12

What is the geometry of pentacarbonyliron(0)?(a) Square planar(b) Tetrahedral(c) Trigonal bipyramidal(d) OctahedralThis question was addressed to me in examination.This intriguing question originated from Bonding in Metal Carbonyls in chapter Coordination Compounds of Chemistry – Class 12

Observe the orbital splitting diagram of a tetrahedral field and find the value of x.(a) 0.178(b) 0.267(c) 0.4(d) 0.44The question was asked in an internship interview.My question is taken from Bonding in Coordination Compounds topic in chapter Coordination Compounds of Chemistry – Class 12

Hexaaquatitanium(III) chloride is a coloured compound that loses its colour on heating.(a) True(b) FalseThe question was asked during an interview for a job.My question is from Bonding in Coordination Compounds topic in portion Coordination Compounds of Chemistry – Class 12

The SCN^– ion is a unidentate ligand.(a) True(b) FalseI got this question by my college professor while I was bunking the class.Query is from Definitions topic in portion Coordination Compounds of Chemistry – Class 12

Optical isomers are also known as __________(a) structural isomers(b) facial isomers(c) meridional isomers(d) enantiomersThis question was posed to me in homework.This interesting question is from Isomerism in Coordination Compounds topic in section Coordination Compounds of Chemistry – Class 12

Which of the following compounds has a meridional isomer?(a) [Fe(NO)5Br]^+(b) [Al(CO)3(NO2)3](c) [K(NH)3)4(NO)2]^+(d) [Fe(H2O)2(CO)2(NO)2]^3+The question was posed to me in quiz.The query is from Isomerism in Coordination Compounds topic in division Coordination Compounds of Chemistry – Class 12

How many donor atoms can EDTA^4- ligand bind through?(a) 2(b) 4(c) 6(d) 8This question was addressed to me by my college director while I was bunking the class.This question is from Definitions in portion Coordination Compounds of Chemistry – Class 12

The oxidation number of the central metal in a coordination entity is always a positive quantity.(a) True(b) FalseThis question was addressed to me in a job interview.My doubt stems from Definitions topic in section Coordination Compounds of Chemistry – Class 12

Identify the Lewis acid in K3[Al(C2O4)3].(a) K^+(b) Al(c) Al^3+(d) [Al(C2O4)3]^3-This question was posed to me in final exam.I need to ask this question from Definitions in division Coordination Compounds of Chemistry – Class 12

Which of the following is the coordination entity in K2[Zn(OH)4]?(a) K^+(b) Zn^2+(c) OH^–(d) [Zn(OH)4]^2-This question was addressed to me during an internship interview.My query is from Definitions topic in portion Coordination Compounds of Chemistry – Class 12

What is the sum of the oxidation number of cobalt in [Co(H2O)(CN)(en)2]^2+and [CoBr2(en)2]^+?(a) +3(b) +4(c) +5(d) +6The question was posed to me in unit test.My doubt is from Werner’s Theory of Coordination Compounds topic in portion Coordination Compounds of Chemistry – Class 12

The coordination entity [CrCl2(ox)2]^3- is optically active.(a) True(b) FalseI had been asked this question in my homework.My doubt stems from Isomerism in Coordination Compounds topic in section Coordination Compounds of Chemistry – Class 12

Which of the following cannot be a ligand?(a) Ni^2+(b) Cl^–(c) H2O(d) NH3I got this question in a national level competition.My doubt stems from Definitions in section Coordination Compounds of Chemistry – Class 12