This section includes 7 InterviewSolutions, each offering curated multiple-choice questions to sharpen your Current Affairs knowledge and support exam preparation. Choose a topic below to get started.
| 1. |
The decomposition of phosphine (PH_(3)) on tungsten at low pressure is a first order reaction. It is because the |
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Answer» SOLUTION :`(t_(1))/(t_(2))=((a_(2))/(a_(1)))^(n-1)` `a_(1)="290 MM of Hg "t_(1)="263 seconds"` `a_(2)="360 mm of Hg "t_(2)="212 seconds"` `(263)/(212)=((360)/(290))^(n-1)` `1.24=(1.24)^(n-1)` `n-1=1` `n=1+1=2` Hence, the REACTION is of second order. |
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| 2. |
In the tet of NO_(3)^(-)ion, the dark brown ring complex [Fe(H_(2)O)_(5)(NO)]SO_(4) is formed which of the following is false for this complex? |
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Answer» The brown ring complex is FORMED between nitric oxide (formed as a result to reduction of the nitrate ION by the `Fe^(2+)` ions) and `Fe^(2+)` ions |
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| 3. |
In the test for iodine, I_(2) is treated with sodium thiosulphate (Na_(2)S_(2)O_(3)) : Na_(2)S_(2)O_(3)+I_(2) to NaI +.. |
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Answer» `Na_(2)S_(4)O_(6)` |
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| 4. |
In the talling of mercury ozone oxidies X to Y, X and Y are respectively |
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Answer» `Hg, Hg(I)O` |
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| 5. |
In the tailing of mercury ozone oxidises X to Y.X and Y are respectively |
| Answer» Answer :A | |
| 6. |
In the tailing of mercury ozone oxidises X to Y, X and Y are respectively |
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Answer» `HG, Hg (I)O` |
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| 7. |
In thesyudy of cholrinatio of propane, fourproducts (A,B Cand D of the formula C_(3)H_(6)Cl_(2) were isolated Each was Futherchorinated toprovetrichloro products (C_(3)H_(5)Cl_(3)) it wasfoundthat A provided one trichoro Product ,B gave two and C and D each gave three whatt are the structural formula of A, B ,C and D? |
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Answer» SOLUTION :Dichoro isomers, `(A) {:(""Cl),(""|),(" "CH_(3)-C-CH_(3)),(""|) ,(""Cl),(""darrCl_(2)),(""Cl),(""|),(CH_(2)Cl-C-CH_(3)),(""|),(""Cl),("(one)"):} (B) {:(""ClCH_(2)CH_(2)CH_(2)Cl),(""darrCl_(2)),(1.Cl_(2)CHCH_(2)CH_(2)Cl_(2)),(2.ClCH_(2)ClCHCH_(2)Cl):}` `( C) {:(CH_(3)CHClCH_(2)Cl),(""darrCl_(2)),(1.CH_(2)ClCHClCH_(2)Cl),(2.CH_(3)CHClCHCl_(2)),(3. CH_(3)C Cl_(2)CH_(2)Cl):} (D) {:(CH_(3)CH_(2)XHXl_(2)),(""darr Cl_(2)),(1. CH_(3)CHClCHCl_(2)),(2.CH_(3)CH_(2)CCl_(3)):}` |
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| 8. |
In the table below, ul(identify) which transformations are alpha-decays and which are beta-decays. |{:(,alpha-decay,beta-decay),(.^(226)Ra rarr^(222)Rn,,),(.^(222)Rn rarr^(218)Po,,),(.^(218)Po rarr^(214)Pb,,),(.^(214)Pb rarr^(214)Bi,,),(.^(214)Bi rarr^(214)Po,,),(.^(214)Po rarr^(210)Pb,,),(.^(210)Pb rarr^(210)Bi,,),(.^(210)Bi rarr^(210)Po,,),(^(210)Po rarr^(206)Pb,,):}| |
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| 9. |
In the systemLaCI_3 (s) +H_2O(g) +"Heat" to LaCIO(s) +2HCI(g), equilibrium is established . More water vapour is added to re-establish the equilibrium . The pressure of water vapour is doubled . The factor by which pressure of HCI is changed is |
| Answer» Answer :B | |
| 10. |
In the system, A(g)+ 2B(g) hArr C(g) starting from 0.276M of A and 0.552M of B, the equilibrium is attained. If equilibrium concentration of B is found to be 0.12 M, then equilibrium constant for the equilibrium is : |
| Answer» ANSWER :C | |
| 11. |
In the synthesis of sodium carbonate, the recovery of ammonia is done by treating NH_(4)Cl with Ca(OH)_(2). The by-product obtained in this process is |
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Answer» `CaCl_(2)` |
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| 12. |
In the synthesis of NH_3 by Haber's process, catalyst is ____and promoter is______. |
| Answer» SOLUTION :Finely divided ion (CATALYST) and molybdenum (PROMOTER). | |
| 13. |
In the synthesis of ammonia from nitrogen and hydrogen gases, if 6xx10^(-2) mole of hydrogen disappears in 10 minutes, the number of moles of ammonia formed in 0.3 minutes is |
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Answer» `1.8xx10^(-2)` Rate `= -(d[N_(2)])/(dt) = (6xx 10^(-2)mol)/(10 min) = 6 XX 10^(-3) mol min^(-1)` Rate of formation of `NH_(3)` `i.e., "" (d[NH_(3)])/(dt) = (2)/(3)(-(d[H_(2)])/(dt))` `= (2)/(3) xx 6 xx 10^(-3) mol min^(-1)` `= 4 xx 10^(-3) mol min^(-1)` Now, if `dt = 0* 3 min`, `NH_(3)` formed `= (4 xx 10^(-3) mol min^(-1))(0.3 min)` `= 1. 2 xx 10^(-3) mol` |
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| 14. |
In the synthesis of ammonia by Haber process , if 60 moles of ammonia is obtained in one hour , then the rate of disapperance of Nitrogen is |
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Answer» 30 mol/min rate = `- (d[N_(2)])/(dt) = -(1)/(3) (d[H_(2)])/(dt) = (1)/(2) (d[NH_(3)])/(dt)` Rate of disappearance of `N_(2)` `= (1)/(2)` of rate of formation of `NH_(3)` `= (1)/(2) xx (60 "mole")/(1"hour")=(1)/(2) xx (60)/(60)` mole/minute = 0.5 mole/minute . |
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| 15. |
In the study of inversion of sucrose in presence of acid, if r_(0),r_(1)" and "r_(oo) represent the polarimetric readings at times 0, t and oo respectively, then at the 50% inversion, which of the following relationship will hold good ? |
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Answer» `r_(t)=r_(0)+r_(oo)` Rotation in time oo = (r_(0) -r_(oo)prop a` 50% inversion means `x = a//2` i.e. `r_(0) -r_(t) = (r_(0) -r_(oo))/(2) or 2 r_(0) - 2 r_(t) = r_(0) - r_(00)` or `2 r_(t) = r_(0) + r_(oo)` |
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| 16. |
In the study of chlorination of propane four products (A,B,C and D) (structural isomerism) of the formula C_3H_6Cl_2were isolated. Each was further chlorinated to provide trichloro products (C_3H_5Cl_3)It was found that A provide one trichloro produce, B gave two and C and D each gave three. It is found that D is optically active. Correct formula of the compound D is |
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Answer» `CH_3"CCl"_2CH_3` |
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| 17. |
In the study of chlorination of propane four products (A,B,C and D) (structural isomerism) of the formula C_3H_6Cl_2were isolated. Each was further chlorinated to provide trichloro products (C_3H_5Cl_3)It was found that A provide one trichloro produce, B gave two and C and D each gave three. It is found that D is optically active. Correct formula of the product of chlorination of B is |
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Answer» `Cl_2 CH CH_2 CH_2 CL` |
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| 18. |
In the study of chlorination of propane four products (A,B,C and D) (structural isomerism) of the formula C_3H_6Cl_2were isolated. Each was further chlorinated to provide trichloro products (C_3H_5Cl_3)It was found that A provide one trichloro produce, B gave two and C and D each gave three. It is found that D is optically active.Formula of the compound A is |
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Answer»
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| 19. |
In the structure given below, the sites S_(1) and S_(2) represent |
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Answer» both octahedral voids |
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| 20. |
In the structure of diborane : |
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Answer» the `B-H` BONDS are ionic |
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| 21. |
In the storage battery during charging |
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Answer» `pH` of the electrolyte INCREASES |
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| 22. |
In the statements regarding P_(4) molecule I) The oxidation state is zero II) The covalency is 4 III) The P-hat(P)bond angle 60^(@) The correct combination is |
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Answer» Only III is correct |
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| 23. |
In the statement of leukaemia ______ is used. |
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Answer» WHITE PHOSPHORUS |
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| 24. |
In the standardization of Na_(2)S_(2)O_(3) using K_(2)Cr_(2)O_(7) by iodometry, the equivalent weight of K_(2)Cr_(2)O_(7) is ("molecular weight")/(X). What is the vlaue of X. |
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Answer» `"So. eq. wt. "=("Molecular w.t.")/(6)` |
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| 25. |
In the standarization of Na_(2)S_(2)O_(3)using K_(2)Cr_(2)O_(7)by iodometry , the equivalent weight of K_(2)Cr_(2)O_(7)is |
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Answer» MOLECULAR WEIGHT /2 |
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| 26. |
In the standardization of Na_(2)S_(2)O_(3) using K_(2)Cr_(2)O_(7) by iodometry, the equivalent weight of K_(2)Cr_(2)O_(7) is |
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Answer» (MOLECULAR weight)/2 `K_(2)OVERSET(+6)(Cr_(2))O_(7)=("molecular weight")/(6)` |
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| 27. |
In the spinel structure, oxides, ions are cubical-closest packed whereas 1/8th of tetrahedral voids are occupied by A^(2+) cation and 1/2 of octahedral voids are occupied by B^(3+)cations. The general formula of the compound having spinel structure is: |
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Answer» `A_2B_2O_4` No. of `B^(3+) = 1/2 xx 4 = 2` No. of `O^(2-) = 8 xx 1/8 + 6 xx 1/2 = 4` `(AB_2O_4)` |
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| 28. |
In the species O_(2), O_(2) ^(- ) and O_(2) ^(2-), the correct decreasing order of bond strength is given as |
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Answer» `O_(2) GT O_(2) ^(+) gt O_(2) ^(-) gt O_(2) ^(2-)` |
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| 29. |
In the solvolysis of which alkyl halide, the tendency of rearrangement is minimum- |
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Answer» cis-1-chloro-2-methylcyclohexane |
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| 30. |
In the Solvay process, the reaction : 2NH_(4)Cl+Ca(OH)_(2)toCaCl_(2)+2NH_(3)+2H_(2)O takes place in : |
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Answer» CARBONATION tower |
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| 31. |
In the solid state PCl_5 exists as |
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Answer» `[PCl_4]^(-)` and `[PCl_6]^(+)` IONS `2PCl_(5) |
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| 32. |
In the solid state which of the following is the structure of analine ? |
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Answer»
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| 33. |
In the solid state nitrogen penotoxide exists as |
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Answer» `NO_2^(-)` and `NO_3^(+)` |
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| 34. |
In the silver plating of copper, K[Ag(CN)_(2)] is used instead of AgNO_(3). The reason is |
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Answer» a thin layer of Ag is FORMED on Cu |
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| 35. |
In the set of the given reactions, acetic acid yielded a product C. CH_(3)COOH overset(PCl_(5))to A underset(anh. AlCl_(3))overset(C_(6)H_(6))to B underset("ether")overset(C_(2)H_(5)MgBr)to C The product C would be |
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Answer» `CH_(3)CH(OH)C_(2)H_(5)` |
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| 36. |
In the series Sc(Z= 21) to Zn ( Z= 30),the enthalpy of atomisation of zinc is the lowest , i.e., 126 kJ mol^(-1) . Why ? |
| Answer» SOLUTION :In the series , Sc to Zn , all ELEMENTS have one or more unpaired electrons except zinc which has no unpaired electron as its outer electronic CONFIGURATION is `3d^(10)4s^(2)`. Hence, atomic intermetallic bonding ( METAL - metal bonding) is WEAKEST in zinc. Therefore, enthalpy of atomisation is lowest. | |
| 37. |
In the series Sc (Z=2) to Zn (Z=30), the enthalpy of atomisation of zinc is the lowest, i.e., 126kJ mol^(-1). Why? |
| Answer» SOLUTION :In zinc, the d-electrons are not involved in a metallic bonding as d-orbitals are OCCUPIED completely, while in all other elements in first transition series, d-electrons participates in metallic bonding. So, Zn hs LOWEST enthalpy of ATOMISATION | |
| 38. |
In the series Sc (Z = 21) to Zn (Z = 30), the enthalpy of atomisation of zinc is the lowest, i.e., 126 kJ mol^(-1). Why ? |
| Answer» SOLUTION :In the series, Sc to Zn, all elements have ONE or more unpaired ELECTRONS except zinc which has no unpaired electron, its outer electronic configuration being `3d^(10)4s^(2)`. Lower the number of unpaired electrons, lower is the metal-metal bonding. HENCE, metal-metal bonding is weakest in zinc. Therefore, ENTHALPY of atomisation is lowest. | |
| 39. |
In the series Sc (Z = 21) to Zn (Z = 30), enthalpy of atomisation of zinc is the lowest, i.e., 126 kJ. Mol^(-1). Why ? |
| Answer» SOLUTION :In the above mentioned SERIES Sc (Z = 21) to Zn (Z = 30), all the METAL atoms have one or more unpaired electrons in their outermost shell. On the contry, ZINC `(3d^(10)4s^(2))` has no unpaired electron in the outershell, leading to very poor interatomic interactions. Therefore, enthalpy of atomisation of zinc is the lowest. | |
| 40. |
In the series reaction Aoverset(K_(2))(rarr)Boverset(K_(2))(rarr)Coverset(K_(2))(rarr)D, if K_(1)gtK_(2)gtK_(3) then the rate determing step of the reaction is |
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Answer» `ARARRB` |
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| 41. |
In the series of reaction C_(6)H_(5)NH_(2)underset(0-5^(@)C)overset(NaNO_(2)//HCl)rarrXunderset(CH_(2)O)overset(HNO_(2))rarrY+N_(2)+HClX and Y are respectively. |
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Answer» `C_(6)H_(5)-N=N-C_(6)H_(5),C_(6)H_(5)N_(2)^(o+)CL^(o+)` `C_(6)H_(5)NO_(2)+N_(2)+HCl` |
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| 42. |
In the series of reaction C_(6)H_(5)NH_(2)overset(NaNO_(2)//HCl)underset(0-5^(@)C)rarr X overset(HNO_(2))underset(H_(2)O)rarr Y+N_(2)+HCl, X and Y are respectively |
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Answer» `C_(6)H_(5)-N=N-C_(6)H_(5), C_(6)H_(5)N_(2)^(+)Cl^(-)` |
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| 43. |
In the series ethane,ethylene and acetyene, the C-H bond energy is : |
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Answer» The same in all the THREE compounds |
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| 44. |
In the series ethane,ethylene and acetylene, the C-H bond energy is |
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Answer» GREATEST in ethylene |
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| 45. |
In the sequences of the following ._(92)Xe^(238) overset(-alpha)to Y overset(-beta)toZ overset(-beta)toL overset(-nx)to._(84)M^(218) the value of n will be |
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Answer» 5 |
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| 46. |
In the sequence of the following reactions CH_(3)OH overset(HI)to CH_(3)I overset(KCN)to CH_(3)OH overset("reduction")to X overset(HNO_(2))to Y X and Y are respectively |
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Answer» `CH_(3)CH_(2)NH_(2) and CH_(3)CH_(2)OH` |
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| 47. |
In the series : ""_(88)^(226)Raoverset(-alpha)to""_(86)^(222)Rnoverset(-alpha)to""_(84)^(218)RaAoverset(-alpha)to""_(82)^(214)RaBoverset(-Beta)to""_(83)^(214)RaC Ra belongs to which period? |
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Answer» V |
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| 48. |
In the sequence of the following nuclear reaction ""_(98)^(238) X overset(-alpha)(to) Y overset(-beta)(to) Z overset(-beta) (to)Loverset(n alpha) (to) ""_(90)^(218) M What is the value of n |
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Answer» 3 `""_(98) Z^(234) to ""_(90) Na^(218) + N(""_(2) alpha^(4))` `234 = 218 + 4N implies n = ((234 - 218)/(4)) = 4 , 98 = 90 + 2N implies n = (8)/(2) = 4` |
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| 49. |
In the sequence of reactions Fe^(3+) (aq) underset(SCN^(-))overset("Excess of")rarr underset(("A"))("Blood red colour")underset(F^(-))overset("Excess of")rarr underset(("B"))("Colourless") Identify A and B. Write their IUPAC names. Explain the hybridisation involved in B and calculate spin only magnetic moment of B. |
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Answer» Solution :`Fe^(3+)(AQ)+3SCN^(-)rarr underset("Trithiocyanato IRON (III)")underset(("A"))underset("Blood RED colour")([Fe(SCN)_(3)])underset(F^(-))overset("Excess of")rarr underset("Hexafluoridoferrate (III)")underset(("B"))underset("Colourless")([FeF_(6)]^(3-))` Hybridisation in `[FeF_(6)]^(3-)=sp^(3)d^(2) "" (becauseF^(-) " is a weak ligand")` In `[FeF_(6)]^(3-), Fe^(3+)` has the configuration `3d^(5)`, i.e., it has 5 unpaired electrons. `THEREFORE` Magnetic moment `= sqrt(n(n+2))=sqrt(5(5+2))=sqrt(35)=5.92` BM. |
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