Class 12 Chemistry · Chapter 5
Short answer:
Is chapter me NCERT ne 29 exercise questions diye hain — IUPAC naming (formula se naam aur naam se formula, dono directions), oxidation state aur coordination number nikaalna, isomerism (ionisation, linkage, coordination, hydrate — structural; geometrical aur optical — stereoisomerism), Valence Bond Theory (hybridisation, inner/outer orbital complex), aur Crystal Field Theory (splitting, high spin/low spin, CFSE) cover hote hain. Yahan 20 representative questions solve kiye gaye hain jo har type ko touch karte hain — naming dono direction me, magnetic moment se unpaired electron count, aur CFT splitting diagram word me describe karna.
Coordination compounds woh complexes hain jinme central metal atom/ion, neutral molecules ya ions (ligands) ke saath coordinate bonds banata hai — aur ye bonds itne strong hote hain ki solution me complex apni identity nahi khota. Werner ne 1893 me sabse pehle inko samjhaya — usse pehle chemists confuse the ki CoCl3.6NH3 jaisa compound kaise possible hai jab Co already apni normal valency satisfy kar chuka hai. Werner ne primary aur secondary valence alag karke bताया — aur yahi coordination chemistry ki neev bani. Aaj ye chapter blood me haemoglobin se lekar cancer treatment (cisplatin) tak, aur photography se lekar electroplating tak har jagah dikhta hai.
Chapter 5 Summary — 5 Minute Revision
1. Werner's Theory (1893)
- Primary valence: ionisable, metal ki oxidation state ke barabar, non-directional. Ye satisfy anions se hoti hai.
- Secondary valence: non-ionisable, coordination number ke barabar, fixed aur directional (isliye geometry fix hoti hai — octahedral, tetrahedral, square planar). Ye satisfy neutral molecules ya anions se hoti hai jo ligand ban ke bracket ke andar aate hain.
- Example: CoCl3.6NH3 asal me [Co(NH3)6]Cl3 hai — 3 Cl- primary valence satisfy karte hain (ionisable, AgNO3 se turant precipitate), 6 NH3 secondary valence (coordination sphere ke andar, bracket me, non-ionisable) satisfy karte hain.
- Werner ne conductivity aur AgNO3 test se predict kiya ki kitne Cl- ions free hain — is data se hi coordination number establish hua.
2. Important Terms
- Coordination entity: central atom/ion + surrounding ligands, jaise [CoCl3(NH3)3].
- Central atom/ion: Lewis acid — electron pair accept karta hai.
- Ligand: Lewis base — electron pair donate karta hai (donor atom se bond banata hai).
- Coordination number (CN): total number of sigma bonds jo ligands central atom ke saath banate hain (chelating ligand ke har donor atom ko alag count karo). [Co(en)3]3+ me CN = 6, kyunki en didentate hai aur 3 en × 2 donor atom = 6.
- Coordination sphere: square bracket ke andar ka portion — central atom + ligands + charge. Bracket ke bahar ka part = counter ion (ionisation sphere).
- Oxidation number: central atom ka hypothetical charge agar saare ligands aur unke bonding electron pairs hata diye jaayein. Roman numeral me likhte hain — Fe(II), Fe(III).
- Homoleptic complex: sirf ek type ka ligand — [Co(NH3)6]3+.
- Heteroleptic complex: do ya zyada type ke ligands — [Co(NH3)4Cl2]+.
3. Ligands — Types
- Unidentate (monodentate): ek hi donor atom se bond — Cl-, NH3, H2O, CN-, CO.
- Didentate (bidentate): do donor atoms — ethylenediamine (en), oxalate (C2O42-).
- Polydentate: multiple donor atoms — EDTA4- hexadentate hai (6 donor atoms — 4 O aur 2 N), ek chelating ligand ka sabse classic example.
- Chelate ligand: jab di- ya polydentate ligand ring bana ke central metal se bandhta hai (chelation) — is ring formation se complex zyada stable hota hai (chelate effect).
- Ambidentate ligand: do alag donor atoms hote hain par ek time pe sirf ek use hota hai — isi wajah se linkage isomerism banta hai.
- NO2- (nitrito-N, N se bonded) vs ONO- (nitrito-O, O se bonded)
- SCN- (thiocyanato, S se bonded) vs NCS- (isothiocyanato, N se bonded)
4. IUPAC Nomenclature Rules (order-sensitive — yahi sabse zyada marks kaatta hai)
- Cation ka naam pehle likho, phir anion (jaise normal ionic compound me) — chahe complex cation ho ya complex anion.
- Coordination entity ke andar: ligands ko alphabetical order me likho — multiplying prefix (di, tri) is order ko affect NAHI karta.
- Multiplying prefixes: simple ligand ke liye di, tri, tetra; jin ligand names me pehle se di/tri/tetra type complexity ho (jaise ethylenediamine) ya bidentate/polydentate ligand ho, unke liye bis, tris, tetrakis (aur ligand ka naam bracket me).
- Anionic ligand ka naam '-o' pe end hota hai: chloro (Cl-), cyano (CN-), oxalato (C2O42-), nitrito (NO2-/ONO-), sulphato (SO42-).
- Neutral ligand apne normal naam se, sivaye: aqua (H2O), ammine (NH3), carbonyl (CO), nitrosyl (NO).
- Agar complex ion me negative charge hai (complex anion), toh central metal ka naam '-ate' suffix ke saath (ferrate for Fe, cuprate for Cu, cobaltate for Co, plumbate for Pb, argentate for Ag).
- Central metal ki oxidation state Roman numeral me, bracket ke andar, metal name ke turant baad — bina space ke jaise Co(III).
- Poora coordination entity ka naam ek hi word ki tarah likhte hain (koi space nahi ligands ke beech, sirf number aur alphabetical prefixes ke through separate).
5. Isomerism
(a) Structural isomerism
- Ionisation isomerism: jab ek ligand aur counter ion apni jagah swap kar lein — [Co(NH3)5Br]SO4 (Br coordination sphere me) vs [Co(NH3)5SO4]Br (SO4 coordination sphere me) — dono different ions solution me dete hain (test: BaCl2 se ek SO42- precipitate dega, doosra nahi).
- Linkage isomerism: ambidentate ligand different donor atom se attach hota hai — [Co(NH3)5(NO2)]2+ (N-bonded, nitrito-N) vs [Co(NH3)5(ONO)]2+ (O-bonded, nitrito-O).
- Coordination isomerism: jab compound me dono cation aur anion complex hon, aur ligands unke beech redistribute ho jaayein — [Co(NH3)6][Cr(CN)6] vs [Cr(NH3)6][Co(CN)6].
- Hydrate (solvate) isomerism: water molecules coordination sphere ke andar ya bahar (free water of crystallisation) — classic example CrCl3.6H2O ke teen forms: [Cr(H2O)6]Cl3 (violet), [Cr(H2O)5Cl]Cl2.H2O (grey-green), [Cr(H2O)4Cl2]Cl.2H2O (dark green) — inka conductivity aur AgNO3 se precipitating Cl- ki quantity alag hoti hai.
(b) Stereoisomerism
- Geometrical isomerism (cis-trans): square planar [MA2B2] type me — cis (same ligands adjacent) aur trans (same ligands opposite). Octahedral [MA3B3] type me fac (facial — 3 same ligand ek face pe) aur mer (meridional — 3 same ligand ek meridian pe, do adjacent + ek opposite pattern).
- Optical isomerism: jab complex apni mirror image ke superimpose na ho paaye (chiral) — mostly octahedral complexes with bidentate ligands jaise [Co(en)3]3+ ya cis-[CoCl2(en)2]+ me dikhta hai. Trans isomer usually achiral (plane of symmetry hota hai) jabki cis isomer chiral hota hai (d aur l forms).
6. Valence Bond Theory (VBT)
- Metal ion apne (n-1)d, ns, np, ya ns, np, nd orbitals ko hybridise karta hai — hybrid orbitals empty hote hain jo ligand se electron pair accept karte hain.
- sp3 → tetrahedral; dsp2 → square planar; sp3d2 (outer d orbital, 4s 4p 4d) → outer orbital octahedral (high spin); d2sp3 (inner d orbital, 3d 4s 4p) → inner orbital octahedral (low spin).
- Inner orbital complex = low spin = strong field ligand use karta hai (n-1)d orbitals.
- Outer orbital complex = high spin = weak field ligand use karta hai nd orbitals.
- VBT ki limitation: colour aur exact magnetic behaviour quantitatively explain nahi kar paata — isliye CFT zyada powerful hai.
7. Crystal Field Theory (CFT)
- Ligands ko point charge/dipole treat karte hain jo metal ke d-orbitals ke paas electrostatic field banate hain — sab d-orbitals free ion me degenerate hote hain, par ligand field aane se ye split ho jaate hain.
- Octahedral field: dx²-y² aur dz² (jo axes ke along hote hain, jahan ligands directly approach karte hain) energy me upar chale jaate hain — ye eg set banate hain. dxy, dyz, dxz (jo axes ke beech me hote hain) energy me neeche rehte hain — ye t2g set banate hain. Splitting energy ko Δo (crystal field splitting energy, octahedral) kehte hain — eg set, t2g se Δo upar hota hai.
- Tetrahedral field: splitting octahedral ke opposite hoti hai — e set (neeche) aur t2 set (upar), kyunki koi bhi d-orbital directly ligand ki taraf point nahi karta. Δt ≈ (4/9)Δo — hamesha weak, isliye tetrahedral complexes almost hamesha high spin hote hain.
- High spin vs Low spin (sirf octahedral d4-d7 ke liye relevant):
- Weak field ligand (chhota Δo, pairing energy P se kam): electrons pehle sab 5 orbitals me akele-akele fill honge (Hund's rule follow) — high spin complex, zyada unpaired electrons.
- Strong field ligand (bada Δo, P se zyada): pehle t2g pura pair ho jaayega, phir hi eg me electron jaayega — low spin complex, kam unpaired electrons. "Strong field ligands pehle electrons ko pair karte hain phir hi upar wale orbital me jaate hain — isi wajah se low spin complex banta hai."
- Crystal Field Stabilisation Energy (CFSE): energy jo system stable hoti hai jab electrons splitted orbitals me redistribute hote hain (compared to degenerate baseline). Octahedral: har t2g electron −0.4Δo, har eg electron +0.6Δo. Formula: CFSE = [−0.4(nt2g) + 0.6(neg)]Δo (pairing energy P alag se add karo agar extra pairing ho weak field baseline se).
- Colour: d-d transition (electron t2g se eg jump) visible light absorb karta hai, complementary colour dikhta hai — isliye [Ti(H2O)6]3+ purple/violet hota hai.
8. Applications
- Metal extraction: Ag aur Au ko [Ag(CN)2]- / [Au(CN)2]- complex bana ke ore se leach karte hain (cyanide process).
- Purification: Ni(CO)4 banake impure Ni ko purify karte hain (Mond process — decompose karke pure Ni wapas milta hai).
- Biological systems: haemoglobin (Fe complex — O2 transport), chlorophyll (Mg complex — photosynthesis), vitamin B12 (Co complex).
- Medicine: EDTA lead poisoning treatment me use hota hai (Pb ko chelate karke excrete karwata hai); cisplatin cancer treatment me.
- Analysis: qualitative/quantitative analysis me — Ni2+ ko DMG (dimethylglyoxime) se detect karte hain, EDTA titration hardness of water measure karne me.
- Catalysis: Wilkinson's catalyst [RhCl(PPh3)3] alkene hydrogenation me.
- Electroplating: silver aur gold ko cyanide complex solutions se electroplate karte hain (smooth deposit).
- Photography: unexposed AgBr ko hypo (sodium thiosulphate) [Ag(S2O3)2]3- complex banake film se dhoya (fix) jaata hai.
Poore Class 12 Chemistry ke handwritten colour notes
IITian & district toppers ke banaye short notes — revision-ready, diagram ke saath. Board se pehle poora syllabus 3 din me revise.
Exercise Questions — Solutions (Q1–Q20)
Q1. Werner's theory ke primary aur secondary valence me difference batao, [Co(NH3)6]Cl3 ke example se.
Primary valence ionisable hoti hai aur oxidation state ke barabar hoti hai — yahan Co ki oxidation state +3 hai, jo 3 Cl- se satisfy hoti hai (ye AgNO3 se turant precipitate denge). Secondary valence non-ionisable, coordination number ke barabar aur directional hoti hai — yahan CN = 6, jo 6 NH3 molecules se satisfy hota hai (bracket ke andar, coordination sphere me).
Q2. Coordination number aur oxidation state nikalo: [Co(NH3)4Cl2]+
Coordination number = 6 (4 NH3 + 2 Cl, sab monodentate). Oxidation state: NH3 neutral (0), Cl- each −1, overall charge +1. x + 4(0) + 2(−1) = +1 → x = +3. Co ki oxidation state = +3.
Q3. Coordination number nikalo: [Pt(en)2Cl2]
en (ethylenediamine) didentate hai — har en 2 donor atoms deta hai. CN = 2×2 (en) + 2 (Cl) = 6.
Q4. IUPAC naam do: [Co(NH3)6]Cl3
Hexaamminecobalt(III) chloride.
Q5. IUPAC naam do: [Pt(NH3)2Cl(NO2)]
Diamminechloridonitrito-N-platinum(II) — ligands alphabetical order me: ammine, chlorido, nitrito. (Agar O-bonded ho toh nitrito-O.) Oxidation state: NH3 0, Cl- −1, NO2- −1, overall neutral → Pt = +2.
Q6. IUPAC naam do: K3[Fe(CN)6]
Potassium hexacyanidoferrate(III). (Complex anion hai isliye '-ate' suffix; Fe oxidation state: x + 6(−1) = −3 → x = +3.)
Q7. IUPAC naam do: [Cr(NH3)3(H2O)3]Cl3
Triamminetriaquachromium(III) chloride. (Alphabetical order: ammine 'a' se pehle aqua 'aq' se — a-m aur a-q compare karo, 'ammine' pehle aata hai.)
Q8. Naam se formula banao: Tetraamminediaquacobalt(III) chloride
[Co(NH3)4(H2O)2]Cl3
Q9. Naam se formula banao: Potassium tris(oxalato)chromate(III)
K3[Cr(C2O4)3] — oxalate bidentate hai isliye 'tris' prefix use hua, 'tri' nahi (confusion avoid karne ke liye jab ligand naam khud 'di/tri' jaisa lage ya complex ho).
Q10. Naam se formula banao: Sodium tetrachloridonickelate(II)
Na2[NiCl4]
Q11. Linkage isomerism kya hai — ek pair example ke saath samjhao.
Jab ambidentate ligand (jiske do alag donor atoms hote hain) different atom se metal ko bond karta hai, tab linkage isomers bante hain. Example: [Co(NH3)5(NO2)]Cl2 (N-bonded, 'nitrito-N') aur [Co(NH3)5(ONO)]Cl2 (O-bonded, 'nitrito-O') — same formula, alag connectivity.
Q12. Ionisation isomerism aur hydrate isomerism me kya difference hai?
Ionisation isomerism me ek ligand aur ek counter-ion apni positions swap karte hain (jaise [Co(NH3)5Br]SO4 vs [Co(NH3)5SO4]Br) — dono solution me different ions dete hain. Hydrate isomerism specifically water molecule ke coordination sphere ke andar/bahar hone se banti hai (jaise CrCl3.6H2O ke 3 forms) — ye ionisation isomerism ka hi ek special case hai jisme swap hone wala ligand H2O hota hai.
Q13. [Pt(NH3)2Cl2] (square planar) ke geometrical isomers describe karo.
Cis isomer: dono NH3 ek dusre ke adjacent (90° angle pe) aur dono Cl bhi adjacent. Trans isomer: dono NH3 ek dusre ke opposite (180° angle pe) aur dono Cl bhi opposite. Ye dono ka anti-cancer activity bhi different hai — cis-platin active hai, trans-platin nahi.
Q14. Octahedral [MA3B3] type complex me fac aur mer isomer kya hote hain?
Fac (facial) isomer me teenon A ligand octahedron ke ek hi face (triangular face) pe hote hain, aur teenon B doosre face pe. Mer (meridional) isomer me A ligands ek meridian (great circle) ke along arrange hote hain — do A adjacent aur ek A doosri A se opposite (90°, 90°, 180° pattern).
Q15. Optical isomerism kaunse complexes me dikhti hai aur kyun?
Optical isomerism un octahedral complexes me dikhti hai jo chiral hote hain — yani unki mirror image unhi pe superimpose nahi hoti, koi plane of symmetry nahi hota. Ye mostly bidentate ligand wale complexes me hoti hai, jaise [Co(en)3]3+ ya cis-[CoCl2(en)2]+. Corresponding trans isomer mostly achiral hota hai (uska plane of symmetry hota hai) isliye optically inactive.
Q16. Valence Bond Theory se [Ni(CN)4]2- ki geometry aur magnetic nature predict karo.
CN- strong field ligand hai. Ni2+ ka configuration 3d8 hai. Strong field ligand ki wajah se 3d electrons pair ho jaate hain, ek empty d-orbital available hoke dsp2 hybridisation deta hai — geometry square planar, aur sab electrons paired hone se complex diamagnetic hota hai.
Q17. [CoF6]3- me high spin ya low spin? CFSE calculate karo (qualitatively bataओ configuration).
F- weak field ligand hai — high spin complex banega. Co3+ ka configuration d6 hai. High spin octahedral d6: t2g4eg2 (Hund's rule follow karke pehle sab 5 orbitals me ek-ek electron, phir 6th electron pair banata hai t2g me). CFSE = [−0.4(4) + 0.6(2)]Δo = (−1.6 + 1.2)Δo = −0.4Δo. 4 unpaired electrons — paramagnetic.
Q18. [Co(NH3)6]3+ me low spin kyun hai? Configuration aur unpaired electron count batao.
NH3 ek moderately strong field ligand hai aur Co3+ (d6) ke saath Δo pairing energy P se zyada hota hai — isliye electrons pehle t2g me pair ho jaate hain, eg khaali rehta hai. Configuration: t2g6eg0 — sab electrons paired, 0 unpaired electron, complex diamagnetic hai.
Q19. Tetrahedral crystal field splitting octahedral se kaise different hai?
Tetrahedral field me koi bhi d-orbital directly ligand ki direction me point nahi karta (ligands cube ke alternate corners pe hote hain), isliye e set (dx²-y², dz²) kam energy pe rehta hai aur t2 set (dxy, dyz, dxz) zyada energy pe — octahedral ke bilkul opposite. Δt hamesha chhota hota hai (≈4/9 Δo) kyunki sirf 4 ligands hote hain aur woh directly kisi orbital ki taraf point nahi karte — isliye tetrahedral complexes almost hamesha high spin hote hain, pairing energy overcome karne jitna Δt nahi hota.
Q20. Coordination compounds ke do biological aur do industrial applications batao.
Biological: (1) Haemoglobin — Fe(II) coordination complex jo O2 transport karta hai blood me. (2) Chlorophyll — Mg coordination complex jo photosynthesis me light absorb karta hai. Industrial: (1) Silver aur gold ki cyanide complex [Ag(CN)2]- bana ke ore se extraction. (2) Ni(CO)4 bana ke Mond process se nickel ki purification.
Important Equations — Ek Nazar Me
| Reference | Detail |
|---|---|
| Spectrochemical series (weak → strong field) | I- < Br- < S2- < SCN- < Cl- < N3- < F- < OH- < C2O42- < H2O < NCS- < py ≈ NH3 < en < NO2- < CN- ≈ CO |
| Octahedral CFT splitting | eg (dx²-y², dz²) upar, t2g (dxy, dyz, dxz) neeche. eg energy = +0.6Δo; t2g energy = −0.4Δo. |
| Tetrahedral CFT splitting | t2 (upar), e (neeche) — octahedral ke opposite. Δt ≈ (4/9)Δo — hamesha weak, isliye almost hamesha high spin. |
| CFSE formula (octahedral) | CFSE = [−0.4 × n(t2g) + 0.6 × n(eg)] Δo (+ mP agar extra pairing hui weak-field baseline se, m = extra pairs) |
| High spin vs low spin rule | Δo < P → weak field ligand → high spin (max unpaired e⁻, Hund's rule). Δo > P → strong field ligand → low spin (pairing pehle, t2g fill hoke phir eg). Sirf d4-d7 configurations me choice hoti hai. |
| IUPAC naming order | 1) Cation pehle, anion baad me → 2) Ligands alphabetical order me (prefix ignore karke) → 3) Multiplying prefix: simple ligand = di/tri/tetra, complex/bidentate ligand = bis/tris/tetrakis → 4) Anionic ligand '-o' pe end (chloro, cyano, oxalato) → 5) Neutral ligand special names: aqua, ammine, carbonyl, nitrosyl → 6) Complex anion ka metal naam '-ate' pe end (ferrate, cuprate) → 7) Oxidation state Roman numeral, bracket me, koi space nahi |
| Common ligand names and denticity | Cl- chlorido (mono) · CN- cyano (mono) · NH3 ammine (mono) · H2O aqua (mono) · CO carbonyl (mono) · NO2- nitrito-N / ONO- nitrito-O (mono, ambidentate) · SCN-/NCS- thiocyanato/isothiocyanato (mono, ambidentate) · en (ethylenediamine) didentate · C2O42- (oxalato) didentate · EDTA4- hexadentate |
↔ Table ko side me swipe karein
Common Mistakes — Yahan Marks Kat te Hain
- Overall charge ignore karke oxidation state galat nikalna. [Co(NH3)4Cl2]+ me students bracket ke bahar ka +1 charge bhool jaate hain aur x + 0 − 2 = 0 laga dete hain (galat Co = +2). Sahi: x + 0 − 2 = +1, isliye Co = +3.
- IUPAC naam me ligands ko multiplying prefix (di/tri) ke basis pe order karna, alphabet ke basis pe nahi. 'Diamminetrichlorido' likhte waqt agar chloro pehle likhna hai kyunki 'tri' hai — ye galat hai. Order hamesha ligand naam ke pehle letter se decide hota hai (prefix ignore karke): ammine ('a') chlorido ('c') se pehle aayega, chahe kitna bhi prefix ho.
- Bis/tris confuse karna simple di/tri prefix se. Bidentate ya complex-naam ligand (jaise ethylenediamine, oxalato) ke liye 'bis(ethylenediamine)' likhna padta hai — 'diethylenediamine' likhna galat hai kyunki confusion hoti hai ki 'di' ligand count ka hissa hai ya naam ka.
- Ionisation isomerism aur hydrate isomerism ko confuse karna. Dono me ligand aur counter-ion swap hota hai — par students CrCl3.6H2O ke saare forms ko 'coordination isomer' bol dete hain jabki ye actually hydrate isomerism hai (ionisation isomerism ka special case), coordination isomerism sirf tab hoti hai jab dono cation aur anion complex hon.
- Weak vs strong field ligand ko galat classify karna. H2O ko strong field aur NH3 ko weak samajh lena common mistake hai — spectrochemical series me actually H2O, NH3 se weaker hai (H2O < NH3 < en < CN-). Yaad rakhne ka tarika: halide ions sabse weak, CO/CN- sabse strong.
- d-electron count galat karna kyunki oxidation state pehle nikalna bhool jaate hain. [Fe(CN)6]3- me students Fe ka neutral atom configuration (3d64s2) use kar lete hain. Sahi tarika: pehle oxidation state nikalo (Fe = +3 yahan), phir d-electron count karo (Fe3+ = 3d5, kyunki 4s electrons pehle nikalte hain ionisation me).
Board-Style Important Questions
- 1 mark: Coordination number ki definition do.
- 1 mark: Ambidentate ligand ka ek example do jo linkage isomerism dikhata ho.
- 2 marks: [Co(NH3)5Cl]Cl2 me Co ki oxidation state aur coordination number calculate karo.
- 3 marks: [Cr(en)3]3+ aur [PtCl2(en)2] me se kaunsa optical isomerism dikhayega aur kyun, samjhao.
- 3 marks: Valence Bond Theory ka use karke [Ni(CN)4]2- ki geometry aur magnetic behaviour explain karo.
- 5 marks: Crystal Field Theory ke according octahedral complex me d-orbitals ka splitting samjhao, aur [CoF6]3- (high spin) tatha [Co(NH3)6]3+ (low spin) ke electronic configuration aur CFSE compare karo.
Aksar Poochhe Jaane Wale Sawaal
Coordination number aur oxidation state me kya farak hai?
Coordination number sigma bonds ka count hai jo ligands central atom se banate hain — geometry decide karta hai. Oxidation state central atom ka hypothetical charge hai jab saare ligand electrons metal ko de diye jaayein — ye ionic character batata hai. Dono independent quantities hain, ek doosre se directly related nahi.
En (ethylenediamine) ko IUPAC naam me 'bis(ethylenediamine)' kyun likhte hain, 'diethylenediamine' kyun nahi?
Kyunki 'diethylenediamine' padhne pe confusion hoti hai ki ye ek naya ligand hai (jaise diethylamine jaisa naam) ya do ethylenediamine molecules. Bis/tris/tetrakis prefix ye clear karta hai ki multiplying number bracket ke andar ke poore ligand naam pe apply ho raha hai, sirf ek part pe nahi.
High spin aur low spin complex me magnetic property kaise different hoti hai?
High spin complex me unpaired electrons zyada hote hain (Hund's rule maximum follow hota hai) isliye ye zyada strongly paramagnetic hote hain. Low spin complex me pairing zyada hoti hai isliye unpaired electrons kam (ya zero, diamagnetic bhi ho sakta hai) — kam paramagnetic ya diamagnetic.
Kya sab octahedral complexes high spin/low spin dikha sakte hain?
Nahi — ye choice sirf d4 se d7 configuration wale metal ions me hoti hai, kyunki inhi configurations me electron ko t2g me pair karna ya eg me bhejna — dono options possible hote hain. d1-d3 aur d8-d10 me sirf ek hi tarika possible hai, high/low spin ka farak hi nahi banta.
Chelate effect kya hota hai aur kyun stability badhata hai?
Jab di- ya polydentate ligand ring bana ke metal se bandhta hai (chelation), toh resulting complex monodentate ligands wale complex se zyada stable hota hai — isko chelate effect kehte hain. Ye mainly entropy factor ki wajah se hota hai: chelating ligand attach hone pe kam total particles release/involve hote hain compared to equivalent monodentate ligands, jisse system ki entropy favourably badhti hai.
EDTA lead poisoning treatment me kaise kaam karta hai?
EDTA (ethylenediaminetetraacetic acid) ek hexadentate ligand hai jo Pb2+ ions ko strongly chelate kar leta hai, ek bahut stable water-soluble complex banake. Ye complex phir kidney ke through body se excrete ho jaata hai — isliye EDTA ko lead poisoning ke treatment me antidote ki tarah use karte hain.
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