🧪 Chemistry · Class 12 · NEET & JEE
Coordination Compounds - Practice Questions with Answers 75 free MCQs on Coordination Compounds, each with its own worked answer and explanation. Study of compounds where a central metal atom is bonded to surrounding ligands. Covers nomenclature, types of isomerism, bonding theories (VBT, CFT), and applications in medicine, photography, and industry.
Take the timed Coordination Compounds chapterwise test → 75 practice questions on Coordination Compounds , sorted Easy → Hard. Try each one first, then open its answer page for the worked explanation. Want the full theory first? Read the Coordination Compounds notes .
Octahedral coordination no. 6 e.g. [Co(NH3)6]3+ Tetrahedral coordination no. 4 e.g. [Ni(CO)4] Square Planar coordination no. 4 e.g. [Pt(NH3)2Cl2] The three common coordination geometries: octahedral (6 ligands), tetrahedral (4 ligands), and square planar (4 ligands in one plane).
Easy - 25 questions Q1.
In K<sub>3</sub>[Fe(C<sub>2</sub>O<sub>4</sub>)<sub>3</sub>], oxalate is bidentate. The coordination number of iron is:
Show answer & explanation →
Q3.
A homoleptic complex is one in which the metal is bound to:
A only anionic ligandsB two different kinds of ligandsC only one kind of donor ligandD only neutral ligandsShow answer & explanation →
Q4.
Which of the following ligands is a chelating (polydentate) ligand?
A Chloride ionB AmmoniaC WaterD Oxalate ionShow answer & explanation →
Q5.
The atom of a ligand that is directly bonded to the central metal is called the:
A donor atomB counter ionC spectator atomD bridging unitShow answer & explanation →
Q6.
A coordination compound consists of a central metal atom surrounded by:
A Ligands (ions or molecules donating electron pairs)B Mainly covalent bonds with little donor-acceptor characterC Mainly ionic bonds formed by complete electron transferD No surrounding atoms or groups whatsoever as generally observedShow answer & explanation →
Q7.
What is a ligand?
A An ion or molecule that donates a lone pair to the metalB The central metal atom around which the structure is builtC The overall charged species formed once the structure is assembledD A neutral complex with no net charge on the whole assemblyShow answer & explanation →
Q9.
What is the name of [Cu(NH<sub>3</sub>)4]2+?
A Tetraamminecopper(II) ionB Copper tetraamine as widely reportedC Diammine copper in standard practiceD Cupric amide under most conditions encounteredShow answer & explanation →
Q10.
EDTA is an example of which type of ligand?
A Hexadentate (6 donor atoms)B Monodentate, donating through only a single atomC Bidentate, donating through exactly two atomsD Tridentate, donating through exactly three atomsShow answer & explanation →
Q11.
A bidentate ligand donates how many electron pairs?
A Two (from two donor atoms)B One, from a single donor atom on the ligandC Three, from three separate donor atoms on the ligandD Six, from six separate donor atoms on the ligandShow answer & explanation →
Q13.
What is the IUPAC name for [Fe(CN)<sub>6</sub>]4-?
A Hexacyanoferrate(II) ionB Hexacyanoferrate(III) ionC Iron hexacyanideD FerrocyanideShow answer & explanation →
Q15.
The chelate effect refers to:
A Extra stability of complexes formed with polydentate ligands due to increased entropyB The particular colour displayed by a coordination complex once it formsC A general magnetic property uniformly shown by every chelated complexD Simply the total count of separate ligand molecules attached to the central metalShow answer & explanation →
Q16.
What does the term 'Werner complex' refer to?
A Classic coordination compounds proposed by Alfred Werner (Nobel 1913)B A purely covalent organic compound unrelated to coordination chemistryC A simple ionic solid lacking any coordinate bondsD An organic polymer formed by repeating monomer unitsShow answer & explanation →
Q17.
CN- is a strong field ligand because:
A It is a good sigma and pi acceptor (back-bonding with metal d orbitals causes large Delta)B It generally carries a negative charge like many weak field ligands also do as frequently observed in practiceC It has an unusually small ionic size compared to other ligands in many documented casesD It happens to contain a nitrogen atom in its structure according to conventional understandingShow answer & explanation →
Q19.
The formula for potassium hexacyanoferrate(III) is:
A K3[Fe(CN)<sub>6</sub>]B K<sub>4</sub>[Fe(CN)<sub>6</sub>]C K[Fe(CN)<sub>6</sub>]D K2[Fe(CN)<sub>6</sub>]Show answer & explanation →
Q20.
Ethylenediamine (en) is a bidentate ligand because it has:
A Two NH<sub>2</sub> donor atomsB One NH<sub>2</sub> groupC A carboxyl groupD A carbon-carbon double bondShow answer & explanation →
Q21.
The primary valence in Werner's theory corresponds to:
A Oxidation state (ionisable valence)B The coordination number, which Werner instead termed secondary valenceC A separate secondary valence distinct from the primary valenceD Simply the total number of ligands bound to the metal centreShow answer & explanation →
Q22.
Which complex is used as an anticancer drug?
A Cisplatin [cis-Pt(NH<sub>3</sub>)<sub>2</sub>Cl<sub>2</sub>]B [Co(NH<sub>3</sub>)<sub>6</sub>]Cl3 in routine practiceC [Fe(CN)<sub>6</sub>]4- overall in most casesD [Cu(NH<sub>3</sub>)4]2+ under typical conditionsShow answer & explanation →
Q23.
Haemoglobin is a coordination complex in which the metal is:
A Fe<sup>2+</sup> (iron II)B Mg<sup>2+</sup> according to standard textbooksC Cu<sup>2+</sup> in general practiceD Co3+ as frequently describedShow answer & explanation →
Q24.
An ambidentate ligand is one that can coordinate through:
A Two different donor atoms (e.g., SCN- via S or N)B Two identical donor atoms positioned on opposite ends of the ligandC Multiple chelate rings formed simultaneously with one metal centreD Oxygen exclusively, regardless of any other potential donor atomsShow answer & explanation →
Medium - 25 questions Q26.
Which one of the following complexes is expected to be diamagnetic?
A [CoF<sub>6</sub>]<sup>3-</sup>B [Fe(H<sub>2</sub>O)<sub>6</sub>]<sup>2+</sup>C [NiCl<sub>4</sub>]<sup>2-</sup>D [Ni(CN)<sub>4</sub>]<sup>2-</sup>Show answer & explanation →
Q27.
The spin-only magnetic moment of [Fe(CN)<sub>6</sub>]<sup>3-</sup> is approximately:
A 3.87 BMB 1.73 BMC 4.90 BMD 5.92 BMShow answer & explanation →
Q28.
The hybridisation of the central metal in the square planar [Ni(CN)<sub>4</sub>]<sup>2-</sup> is:
A sp<sup>3</sup>B sp<sup>3</sup>dC dsp<sup>2</sup>D d<sup>2</sup>sp<sup>3</sup>Show answer & explanation →
Q29.
How many ions does 1 mole of [Co(NH<sub>3</sub>)<sub>5</sub>Cl]Cl<sub>2</sub> furnish in aqueous solution?
A 3 ionsB 2 ionsC 4 ionsD 5 ionsShow answer & explanation →
Q31.
Ionisation isomers differ in:
A Ions inside and outside the coordination sphereB Arrangement of ligands around the metal in typical laboratory settingsC The metal's oxidation state under usual circumstancesD The number of ligands according to most researchersShow answer & explanation →
Q32.
[Co(NH<sub>3</sub>)5Cl]SO4 and [Co(NH<sub>3</sub>)5SO4]Cl are examples of:
A Ionisation isomersB Geometrical isomersC Optical isomersD Linkage isomersShow answer & explanation →
Q33.
Geometrical isomerism (cis-trans) is possible in square planar complexes with:
A MA2B2 type (e.g., [Pt(NH<sub>3</sub>)<sub>2</sub>Cl<sub>2</sub>])B MA4 type complexes, which show no geometric isomerism in square planar geometryC MA6 type complexes, which are not square planar at allD MA2 type complexes, which have too few ligands to show cis-trans isomerismShow answer & explanation →
Q34.
In an octahedral complex MA3B3, the two geometrical isomers are:
A Facial (fac) and meridional (mer)B Cis and transC Clockwise and anticlockwiseD Alpha and betaShow answer & explanation →
Q35.
Optical isomers in coordination chemistry (enantiomers) are non-superimposable mirror images. A classic example is:
A [Co(en)3]3+ (tris-chelate)B [Co(NH<sub>3</sub>)<sub>6</sub>]3+ in the majority of cases studiedC [Ni(CN)4]2- as widely reportedD [CrCl6]3- in standard practiceShow answer & explanation →
Q36.
What does VBT (Valence Bond Theory) explain about coordination compounds?
A Hybridisation of metal orbitals and geometry; doesn't explain colour or magnetism wellB Every property of the complex, including its colour and magnetism in full detailC Mainly the magnetic behaviour of the complex and nothing else as frequently observed in practiceD Mainly the kinetics and reaction rates of the complex's ligand exchange in many documented casesShow answer & explanation →
Q37.
In VBT, inner orbital complexes use d orbitals from:
A The inner (n-1)d subshell (e.g., 3d with 4s, 4p for period 4 metals)B The outer nd subshell instead of the inner (n-1)d subshell under most conditions encounteredC 4f orbitals borrowed from the lanthanide series as frequently observed in practiceD 5d orbitals regardless of which period the metal belongs to in many documented casesShow answer & explanation →
Q38.
In CFT, the crystal field stabilisation energy (CFSE) for d<sup>6</sup> high spin in octahedral field is:
A -0.4 Delta_o (4 in t<sub>2g</sub> × -0.4 + 2 in eg × +0.6 = -1.6 + 1.2 = -0.4 Delta_o)B Zero, since the high-spin d<sup>6</sup> arrangement gives no net stabilisationC -1.2 Delta_o, the value corresponding instead to a d<sup>3</sup> configurationD -2.4 Delta_o, the value corresponding instead to a low-spin d<sup>6</sup> configurationShow answer & explanation →
Q39.
Linkage isomers differ in:
A The donor atom through which an ambidentate ligand coordinates (e.g., NO<sub>2</sub>- via N or O)B Their overall molecular formula, which differs between the two isomers according to conventional understandingC The oxidation state assigned to the central metal atom in routine practice overallD The total number of electrons present in the complex in most cases under typical conditionsShow answer & explanation →
Q40.
Prussian blue is:
A Fe4[Fe(CN)<sub>6</sub>]3 (mixed valence Fe<sup>2+</sup>/Fe<sup>3+</sup> complex with CN- bridges)B A simple aqueous CuSO<sub>4</sub> solution with little iron present according to conventional understandingC Plain FeCl<sub>3</sub> dissolved in water with little cyanide bridgesD K3[Fe(CN)<sub>6</sub>], the separate potassium ferricyanide salt in routine practiceShow answer & explanation →
Q41.
The spectrochemical series for common ligands in order of increasing field strength:
A I- < Br- < Cl- < F- < OH- < H<sub>2</sub>O < NH<sub>3</sub> < en < CN- < COB CO < CN- < NH<sub>3</sub> < F- < Cl-, listed in the reverse field-strength orderC All ligands shown to have identical field strength toward any metalD The field strength ranking depending entirely on which metal is usedShow answer & explanation →
Q42.
How does the EDTA complex [EDTA-Ca]2- help in water softening?
A It sequesters Ca<sup>2+</sup> and Mg<sup>2+</sup> by forming very stable (high K) chelates, preventing them from causing hardnessB It precipitates the calcium and magnesium ions out of solution as insoluble solid salts according to standard textbooksC It promotes additional ionisation of the surrounding bulk water molecules in general practice as frequently describedD It generally raises the overall pH of the water without complexing any of the ions in most textbook accountsShow answer & explanation →
Q43.
Coordination compounds with the same formula and donor atoms but different arrangements are called:
A Stereoisomers (including geometric and optical isomers)B Constitutional (structural) isomers, which differ in connectivity insteadC Resonance structures of a single fixed arrangement of atomsD Tautomers related by a simple proton-shift equilibriumShow answer & explanation →
Q44.
The effective atomic number (EAN) rule by Sidgwick states:
A Metal in a complex acquires electrons from ligands to achieve the electron count of the next noble gasB The metal instead loses electrons to its surrounding ligands in the complex during normal conditionsC Ligands serve mainly to fix the oxidation state with little electron-count rule involved as generally observedD The coordination number is usually numerically equal to the oxidation state in typical laboratory settingsShow answer & explanation →
Q45.
Which of the following is an outer orbital complex (uses nd orbitals, sp<sup>3</sup>d<sup>2</sup>)?
A [CoF6]3- (F- is weak field, uses 4d orbitals, sp<sup>3</sup>d<sup>2</sup>, high spin)B [Co(CN)6]3-, an inner orbital low-spin complex using 3d orbitalsC [Co(NH<sub>3</sub>)<sub>6</sub>]3-, an inner orbital low-spin complex using 3d orbitalsD [Fe(CO)<sub>5</sub>], a zero-valent carbonyl complex with trigonal bipyramidal geometryShow answer & explanation →
Q46.
The stability constant (formation constant) Kf of a complex indicates:
A The extent to which the complex forms in solution (higher Kf = more stable)B The specific colour the complex displays once largely formed under usual circumstancesC The melting point of the solid complex once isolated according to most researchersD The overall molecular weight of the formed complex in the majority of cases studiedShow answer & explanation →
Q47.
Which complex shows the trans effect most prominently?
A Square planar Pt(II) complexesB Octahedral Co(III) as widely reportedC Tetrahedral Ni(II) in standard practiceD Linear Au(I) under most conditions encounteredShow answer & explanation →
Q48.
Coordination isomers differ by:
A Exchange of ligands between two complex centres in a compound with both + and - complex ionsB The oxidation state formally assigned to each central metal ion present in the saltC The total number of ligands individually attached to each of the two metal centresD Geometry alone, while keeping an identical ligand distribution shared between centresShow answer & explanation →
Q49.
The role of EDTA in analytical chemistry (complexometric titration) is:
A It forms 1:1 stable complexes with metal ions at controlled pH, allowing accurate quantificationB It functions generally as a strong acid that lowers the solution's pH as frequently observed in practiceC It precipitates the target metal ions as an insoluble solid in many documented cases according to conventional understandingD It acts mainly as a visual indicator that changes colour at the endpoint in routine practiceShow answer & explanation →
Q50.
Which coordination compound was historically important in proving Werner's theory?
A [Co(NH<sub>3</sub>)<sub>6</sub>]Cl3 and its series of Co-NH<sub>3</sub>-Cl complexesB NaCl, a simple ionic salt with no coordinate covalent bondingC [Pt(CN)4]2-, a square planar complex unrelated to Werner's original seriesD K<sub>4</sub>[Fe(CN)<sub>6</sub>], the separate potassium ferrocyanide saltShow answer & explanation →
Hard - 25 questions Q51.
Which of the following complex ions has a spin-only magnetic moment of about 5.92 BM?
A [Co(NH<sub>3</sub>)<sub>6</sub>]<sup>3+</sup>B [Fe(CN)<sub>6</sub>]<sup>4-</sup>C [Mn(H<sub>2</sub>O)<sub>6</sub>]<sup>2+</sup>D [Ni(CN)<sub>4</sub>]<sup>2-</sup>Show answer & explanation →
Q53.
For a low-spin d<sup>6</sup> octahedral complex, the crystal field stabilisation energy (excluding pairing energy) is:
A -2.4 Delta<sub>o</sub>B -1.6 Delta<sub>o</sub>C -0.4 Delta<sub>o</sub>D -1.2 Delta<sub>o</sub>Show answer & explanation →
Q54.
Electron pairing to give a low-spin octahedral complex occurs when:
A the pairing energy P exceeds Delta<sub>o</sub>B Delta<sub>o</sub> exceeds the pairing energy PC the ligand is a weak field ligandD the metal ion is in a low oxidation stateShow answer & explanation →
Q55.
Compared with [Fe(H<sub>2</sub>O)<sub>6</sub>]<sup>3+</sup>, the ion [Fe(CN)<sub>6</sub>]<sup>3-</sup> has:
A more unpaired electrons and is high spinB the same number of unpaired electronsC fewer unpaired electrons and is low spinD no d electrons at allShow answer & explanation →
Q56.
Using CFSE, predict whether [Co(CN)6]4- (Co2+, d7) is high or low spin:
A Low spin: CN- is strong field, large Delta causes maximum pairing (t<sub>2g</sub><sup>6</sup> eg1, 1 unpaired)B High spin with three unpaired electrons distributed across t<sub>2g</sub> and eg in the majority of cases studiedC Largely diamagnetic with zero unpaired electrons in this d7 ion as widely reportedD High spin with five unpaired electrons, the maximum possible for d7 in standard practiceShow answer & explanation →
Q57.
The stability of chelate complexes is explained by:
A Chelate effect = combination of enhanced entropy (more particles released on complex formation) and entropic contribution to Gibbs energyB Each individual metal-donor bond within the chelate ring being inherently far stronger than usual under most conditions encounteredC The chelate generally containing a much larger total number of covalent bonds overall as frequently observed in practice in many documented casesD The chelate possessing a far greater degree of ionic character than ordinary monodentate complexes according to conventional understandingShow answer & explanation →
Q58.
The trans effect series in Pt(II) chemistry ranks ligands by their ability to labilise the trans position. The order includes:
A CN-, CO, NO+ > H- > CH<sub>3</sub><sup>-</sup> > PR<sub>3</sub> > SC(NH<sub>2</sub>)<sub>2</sub> > NH<sub>3</sub> > NR<sub>3</sub> > Cl- > Br- > I- > H<sub>2</sub>OB H<sub>2</sub>O > Cl- > CN-, listed in the reverse order of true trans-labilising strengthC All ligands shown to labilise the trans position with identical strengthD Only the halogen ligands shown to exhibit any trans effect at allShow answer & explanation →
Q59.
Which of the following octahedral complexes shows optical isomerism?
A [Co(en)<sub>2</sub>Cl<sub>2</sub>]+ (cis form is chiral)B [Co(NH<sub>3</sub>)<sub>6</sub>]3+, a perfectly symmetric homoleptic complex with a plane of symmetryC [CoCl<sub>6</sub>]3-, a perfectly symmetric homoleptic complex with a plane of symmetryD trans-[Co(en)<sub>2</sub>Cl<sub>2</sub>]+, which possesses an internal mirror plane and is achiralShow answer & explanation →
Q60.
The pi-backbonding (back-donation) in metal carbonyl complexes: CO donates sigma electrons to the metal, and the metal:
A Donates electron density from filled d orbitals back into the CO pi* orbital (backbonding), strengthening M-C and weakening C-OB Instead generally accepts additional pi electron density directly back from the filled CO pi orbital in routine practice overallC Transfers most of its electrons to the CO ligand mainly through an ionic electron-transfer mechanism in most cases under typical conditionsD Forms highly no pi-type interaction with CO, relying mainly on simple sigma bonding according to standard textbooks in general practiceShow answer & explanation →
Q61.
Why is [PtCl<sub>4</sub>]2- square planar while [NiCl<sub>4</sub>]2- is tetrahedral?
A Pt<sup>2+</sup> (5d<sup>8</sup>) has larger CFSE favouring square planar; Ni<sup>2+</sup> (3d<sup>8</sup>) has smaller Delta and the pairing energy penalty for square planar is not compensatedB Platinum's much greater atomic mass relative to nickel is what forces the square planar shape on its own as frequently described in most textbook accountsC The chloride ligand bound to nickel is somehow physically larger than the same chloride ligand bound to platinum during normal conditions as generally observedD Nickel is supplied with extra coordinating chloride ligands in solution that platinum is largely denied access to in typical laboratory settingsShow answer & explanation →
Q62.
The spectrochemical series order is explained by sigma and pi donation/acceptance. Why does H<sub>2</sub>O cause smaller splitting than NH<sub>3</sub>?
A H<sub>2</sub>O is a pi-donor (lone pairs on O donate into empty metal d orbitals), decreasing effective Delta; NH<sub>3</sub> has no pi-donor capacityB Water is actually claimed to be a far stronger sigma donor than ammonia toward the metal centre under usual circumstances according to most researchersC Ammonia is instead claimed to accept pi electron density back from the filled metal d orbitals in the majority of cases studiedD Water's oxygen donor atom is generally claimed to be much larger than ammonia's nitrogen donor atom as widely reported in standard practiceShow answer & explanation →
Q63.
Prussian blue reaction: K<sub>4</sub>[Fe(CN)<sub>6</sub>] (potassium ferrocyanide) added to FeCl<sub>3</sub> gives:
A Prussian blue (KFe[Fe(CN)<sub>6</sub>]) intensely blue precipitateB A pale yellow precipitate forming instead of any blue colourC A deep red colouration with no precipitate forming at allD No visible reaction occurring between the two reagentsShow answer & explanation →
Q64.
The Irving-Williams series describes:
A The stability order of divalent transition metal complexes: Mn<sup>2+</sup> < Fe<sup>2+</sup> < Co2+ < Ni<sup>2+</sup> < Cu<sup>2+</sup> > Zn<sup>2+</sup>B The spectrochemical series ranking ligands by field strength instead under most conditions encounteredC The trans effect series ranking ligands by their labilising power in Pt(II) complexes as frequently observed in practiceD The general stability ranking of different oxidation states for one metal in many documented casesShow answer & explanation →
Q65.
Which of the following has the most CFSE stabilisation in an octahedral field?
A d<sup>3</sup> (t<sub>2g</sub><sup>3</sup>, CFSE = -1.2 Delta_o) and d<sup>6</sup> low spin (t<sub>2g</sub><sup>6</sup>, CFSE = -2.4 Delta_o)B d<sup>0</sup>, which by definition has zero d electrons and therefore zero CFSEC d<sup>10</sup>, which has all orbitals fully occupied giving zero net CFSED d<sup>5</sup> high spin, which has one electron in every orbital giving zero net CFSEShow answer & explanation →
Q66.
The reaction [PtCl<sub>4</sub>]2- + 2NH<sub>3</sub> → cis-[Pt(NH<sub>3</sub>)<sub>2</sub>Cl<sub>2</sub>] uses the trans effect of Cl- to control the product. The mechanism:
A First NH<sub>3</sub> goes to any position; second NH<sub>3</sub> goes cis to the first Cl- (Cl- labilises trans site, so second substitution is trans to Cl-)B Both ammonia ligands are said to substitute in a largely random, loosely controlled order overall in most cases under typical conditionsC The second NH<sub>3</sub> ligand is said to substitute specifically trans to the first NH<sub>3</sub> ligand instead according to standard textbooks in general practiceD Chloride is said to act generally as a passive spectator ion with little influence on the order as frequently described in most textbook accountsShow answer & explanation →
Q67.
Which of the following statements about EDTA (ethylenediaminetetraacetate) is correct?
A It is hexadentate (2 N + 4 O donor atoms) and forms thermodynamically very stable 1:1 chelates with most metal ionsB It is generally bidentate, donating through mainly two of its six potential donor atoms according to conventional understandingC It is said to bind mainly to transition metal ions and not to any s-block cations in routine practice overallD It is said to become notably unstable once the surrounding solution pH rises above 7 in most cases under typical conditionsShow answer & explanation →
Q68.
In coordination chemistry, the 'symbiosis principle' states:
A Hard (sigma-donor) ligands stabilise hard metal centres; soft (pi-acceptor) ligands stabilise soft centres (HSAB principle applied to complexes)B Every ligand type is said to behave in an largely equivalent way regardless of hard or soft donor character according to standard textbooksC Mainly strong field ligands such as CN- are said to ever be capable of forming any reasonably stable complex in general practice as frequently describedD The coordination number on its own is said to be the single factor that largely determines complex stability in most textbook accounts during normal conditionsShow answer & explanation →
Q69.
The fluxional behaviour of [Fe(CO)<sub>5</sub>] (trigonal bipyramidal) refers to:
A Rapid exchange of axial and equatorial CO positions at room temperature via Berry pseudorotationB A largely fixed, rigid structure with little exchange between CO positions as generally observedC Permanent loss of one CO ligand followed by its slow recoordination in typical laboratory settingsD Spontaneous ring formation among the five coordinated CO ligands under usual circumstancesShow answer & explanation →
Q70.
For a d<sup>8</sup> metal ion in square planar field, the dx2-y2 orbital is highest in energy because:
A It points directly at the four ligands (sigma interaction); the other d orbitals are less directly aligned with ligandsB It generally happens to contain more electrons than the other four d orbitals combined according to most researchersC The d<sup>8</sup> electron configuration is said to fill this particular orbital last by convention in the majority of cases studiedD The four surrounding ligands are positioned specifically so as to avoid this orbital largely as widely reported in standard practiceShow answer & explanation →
Q71.
Cisplatin's anticancer activity is due to:
A Cross-linking DNA by displacing Cl- with purine N-donors (N7 of guanine), distorting DNA helixB Generally releasing free toxic platinum ions that poison the entire cell under most conditions encounteredC Directly inhibiting a specific metabolic enzyme without touching DNA as frequently observed in practiceD Binding to and disrupting the lipid bilayer of the cell membrane in many documented casesShow answer & explanation →
Q72.
The total number of isomers (including geometric and optical) for [Co(en)(NH<sub>3</sub>)<sub>2</sub>Cl<sub>2</sub>]+ is:
A Five (cis and trans geometric isomers, with the cis form giving three: two cis diastereomers of en orientation and optical isomers)B Just two isomers in total, counting mainly a single cis form and a single trans form according to conventional understanding in routine practiceC Exactly three isomers in total, largely ignoring any optical activity within the cis form overall in most cases under typical conditionsD Mainly one single possible isomer, since the en ligand is said to fix a unique overall geometry according to standard textbooksShow answer & explanation →
Q73.
In MO theory treatment of octahedral complexes, which MO is responsible for the colour (d-d transition)?
A t<sub>2g</sub> to eg* transition (technically t<sub>2g</sub> to eg MO; the antibonding eg* in MO theory corresponds to eg in CFT)B A simple sigma bonding to sigma antibonding transition occurring within the ligand framework in general practiceC A pi bonding to pi antibonding transition localised largely on the surrounding ligand atoms as frequently describedD A deep core 1s to 2s electronic transition occurring within the central metal atom itself in most textbook accountsShow answer & explanation →
Q74.
The spectrochemical series and the nephelauxetic series differ in that:
A Spectrochemical series ranks field strength (Delta); nephelauxetic series ranks the ability to expand d orbital size (reduce electron repulsion, measured by beta)B The two series are claimed to be in fact largely identical in highly everything that each one measures during normal conditions as generally observed in typical laboratory settingsC The spectrochemical series is claimed to exist mainly to classify complex colour and to serve no other purpose under usual circumstances according to most researchersD The nephelauxetic series is claimed to instead classify coordination complexes mainly by their geometric isomer type in the majority of cases studied as widely reportedShow answer & explanation →
Q75.
In the complex [Co(NH₃)₆]³⁺, cobalt(III) with the strong-field NH₃ ligand uses the hybridisation:
A sp³ tetrahedralB dsp² square planarC sp³d² outer orbitalD d²sp³ inner orbitalShow answer & explanation →