IIT-JEE 2006 Solutions by MOMENTUM (questions based on memory of students) CHEMISTRY

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1 IIT JEE 006 IIT-JEE 006 Solutios by MMENTUM (questios based o memory of studets) CHEMISTRY INSTRUCTINS: (i) Questio o. 1 to 1 has oly oe correct optio. You will be awarded marks for right aswer ad 1 mark for wrog aswer. (ii) Questio o. 1 to 0 has oe or more tha oe correct optio(s). You will be awarded 5 marks if you aswer all correct optios ad oly correct optio(s) ad 1 mark will be awarded for wrog aswer. (iii) (iv) (v) Questio o. 1 to are based o small write up first go through it the aswer these questios. You will be awarded 5 marks for right aswer ad marks for wrog aswer. Questio o. to 6 are subjective problems. Circle their correct aswers. There is o egative markig for it. Each questio carries 6 marks. Questio o. 7 to 40 carry 6 marks each. These may have more tha oe correct optios. There is o egative markig for these. 1. Arrage the followig compouds i the order of icreasig boilig poit (I) Hydroxy bezee (II) ortho dihydroxy bezee (III) meta dihydroxy bezee (IV) para dihydroxy bezee (a) (IV) > (III) > (II) > (I) (b) (III) > (IV) > (II) > (I) (c) (II) > (III) > (I) > (IV) (d) (I) > (II) > (III) > (IV) Normally compoud havig large molar mass boils at higher temperature. So compoud (I) will have the least boilig poit. I remaiig isomeric dihydroxy bezees compoud (II) will ivolve extesive itramolecular hydroge bodig. While compoud (IV) will ot exhibit itramolecular hydroge bodig rather form itermolecular hydroge bodig. (IV) > (III) > (II) > (I). If excess of KCN be added to copper sulphate solutio it losses its blue colour due to the formatio of (a) [Cu(CN) 4 ] (b) [Cu(CN) 4 ] (c) [Cu(H) ] (d) CuCN CuS 4 KCN Cu(CN) K S 4 Cu(CN) CuCN ½(CN) ustable pseudo haloge CuCN KCN K [Cu(CN) 4 ] colourless. B(H) NaH Na[B(H) 4 ] (aq) Which of the followig is the best catalyst to take this reactio i forward directio (a) cis1, diol (b) tras1, diol (c) borax (d) Na HB 4 Boric acid is a very weak acid. It does ot react with alkali explicitly. However, the weak orthoboric acid may be coverted ito comparatively strog moobasic acid by additio of ay cis1, diol to pull the reactio i forward directio sigificatly. MMENTUM, 5, Wright Tow, Jabalpur (M.P.), Ph.(0761) , 40541

2 IIT JEE A process A B is difficult to occur directly istead it takes place i three successive steps. C A B ΔS(A C) = 50 ΔS(C ) = 0 ΔS(B ) = 0 The etropy chage for the process A B is (a) 100 (b) 60 (c) 100 (d) 60 A C ; ΔS = 50 C ; ΔS = 0 B; ΔS = 0 For A B: ΔS = = 60 (d) 5. The bod legth i C is 1.18 Å. What will be the bod legth of C i Fe(C) 5 (a) 1.8 Å (b) 1.18 Å (c) Å (d) Å The metal (Fe) makes the back bodig to C. The metal to ligad bodig creates a syergic effect which stregthes the bod betwee C ad the metal (Fe). Which results i the cotractio of C bod legth. (d) 6. The correct IUPAC ame of C 6 H 5 C is (a) Bezee carboyl chloride (b) Bezoyl chloride (c) Chloropheyl ketoe (d) Pheylchloride ketoe It s trivial ame bezoyl chloride is itself accepted ame i IUPAC system. 7. CH CH = CH N? The product of the followig reactio is (a) CH CH CH N (c) CH CH CH N (b) CH CH CH N (d) N CH CH CH CH CH = CH N CH CH CH CH CH CH N N 8. Whe bezee sulphoic acid ad para itropheol are heated separately with NaHC, the gases evolved are respectively (a) S, N (b) S, N (c) S, C (d) C, C Both bezee sulphoic acid ad para itropheol are stroger acid tha carboic acid so the actual reactio i both cases would be HC H C H (d) MMENTUM, 5, Wright Tow, Jabalpur (M.P.), Ph.(0761) , 40541

3 IIT JEE CH R NH KH? H K What is the product? (a) R CN (b) R N C (c) R N C (d) RCH NH This is carbylamie reactio which goes as R NH CH KH (c) R N C K H 10. If C be passed ito water, what will remai preset i solutio (a) C, H C, C, HC (b) HC, C (c) HC, C (d) C, HC C H H C H C HC H HC H C 11. A aqueous solutio of metal salt is give. NH 4 ad NH 4 H are added to it ad white precipitate is formed. Some part of precipitate remais i dissolved state as well. The above solutio that dissolves i NH 4 H is of (a) Z(H) (b) Al(H) (c) Mg(H) (d) Ca(H) Z NH 4 H Z(H) NH 4 Z(H) 4NH 4 [Z(NH) 4 ] H H 1. The molar heat capacity of a mooatomic gas for which the ratio of pressure ad volume is oe. (a) 4/ R (b) / R (c) 5/ R (d) zero I geeral the molar heat capacity for ay process is give by R C = C V whe PV = costat 1 P Here = 1 i.e. PV 1 = costat V R C = R C = R 1. Compoud (I) ca be obtaied from which of the followig compoud by heatig with alkali followed by acid hydrolysis C Lactoe (I) MMENTUM, 5, Wright Tow, Jabalpur (M.P.), Ph.(0761) , 40541

4 IIT JEE 006 C CH CH (a) CH (b) CH CCH CH (c) CH CH CH C H Itramolecular caizzaro CH H (d) H CH CH CH H H Δ / H C Al 14. CH CH CH Fid major products (P) ad (Q) are respectively (P) (Q) Ph H H (a) ad CH CCH (b) ad CH CCH (c) ad CH CH CH (d) ad CH CH CH CH H Al CH CH CH / H Δ = C (P) (Q). I Haber process for sythesis of ammoia N H NH ; ΔH < 0 Pick the correct statemet (a) Additio of catalyst does ot chage K p but chages ΔH. (b) At equilibrium, G = NH G N G H (where G is Gibbs free eergy) (c) At higher temperature it icreases the rate of forward ad backward reactio by a factor of. (d) At 400 K additio of catalyst will icrease forward reactio by times while reverse reactio rate will be chaged by 1.7 times. At equilibrium state ΔG = 0 for ay reactio. Therefore, ΔG = G P G R G G G = ( ) N H NH MMENTUM, 5, Wright Tow, Jabalpur (M.P.), Ph.(0761) , 40541

5 IIT JEE Give: Ag NH Ag(NH ) ; K 1 = Ag(NH ) NH [Ag(NH ) ] ; K = The equilibrium costat for the reactio Ag NH [Ag(NH ) ] is (a) (b) (c) (d) Equilibrium costat K = K 1 K = = There is a mixture of lowest molecular weight ketoe ad its ext homologue. It is treated with hydroxyl amie whe a mixture of oximes is obtaied. (a) oximes are obtaied (b) oximes are obtaied (c) oe of the oximes is optically active (d) All oximes are optically active The lowest molecular weight ketoe is C ad its ext higher homologue is CH C H C = NH H C = N H (I) H H C = NH H C = N C = N Et Et H Et (II) (III) 18. (CH ) CH CH CH Fractio (N) mixture of isomeric products C5H 11 (F) istillatio The umber of compouds formed respectively for (N) ad (F) are (a) 6,6 (b) 6,4 (c) 4,4 (d), * CHCH CH CH CH CH CH & its eatiomer C CH CH CH CH CH & its eatiomer * CH CH CH Sice, eatiomer have early same physical properties therefore o fractioal distillatio we will get just four distict compouds without resolutio. MMENTUM, 5, Wright Tow, Jabalpur (M.P.), Ph.(0761) , 40541

6 IIT JEE C A Z IEAL GAS B P PV where Z =, RT a = Va der Waal s costat for pressure correctio b = Va der Waal s costat for volume correctio Pick the oly icorrect statemet (a) for gas A, if a = 0, the compressibility factor is directly proportioal to pressure (b) for gas B, if b = 0, the compressibility factor is directly proportioal to pressure. (c) for gas C, a 0, b 0, it ca be used to calculate a ad b by givig lowest P value ad its itercept with Z = 1 (d) slope for all three gases at high pressure is positive. (c) 0. Whe MgS 4 ad NH 4 is added alog with Na P 4 a white precipitate is formed. What is it? (a) Mg(NH 4 )P 4 (b) MgS 4.Mg (c) Mg (P 4 ) (d) MgS 4.Mg(P 4 ) MgS 4 NH 4 Na P 4 Mg(NH4)P 4 Na S 4 Na White ppt. Passage I Ni Ni KCN excess K excess Complex (A) Complex (B) The coordiatio umber of ickel i both complexes (A) ad (B) is The IUPAC ame of complex (A) ad (B) are (a) Potassium tetracyaoicklate(ii) ad Potassium tetrachloroicklate(ii) (b) Potassium tetracyaoickel(ii) ad Potassium tetrachloroickel(ii) (c) Potassium cyaoicklate(ii) ad Potassium chloroicklate(ii) (d) Potassium cyaoickel(ii) ad Potassium chloroickel(ii) (a). Which of the followig is correct? (a) Complex (A) is diamagetic ad complex (B) is paramagetic (b) Complex (A) is paramagetic ad complex (B) is dimagetic (c) Complex (A) with cyao is paramagetic with two upaired electros ad (B) is diamagetic. (d) Complex (A) with cyao is diamagetic ad complex (B) with chloro is paramagetic with two upaired electros. MMENTUM, 5, Wright Tow, Jabalpur (M.P.), Ph.(0761) , 40541

7 IIT JEE 006 For [Ni 4 ] Ni = [Ar] d 8 4s ; Ni = [Ar]d 8 Ni : d 4s 4p sp beig weak field ligad is uable to pair up the electros ad Ni eeds four empty orbitals to accommodate four ligad. Thus, [Ni 4 ] shows sp hybridizatio ad tetrahedral shape. Magetic momet = ( ) =.8 BM For [Ni(CN) 4 ] : Ni = [Ar]d 8 d 4s 4p Ni : dsp CN is a strog field ligad so forces the d electros to pair up to give oe d orbital vacat. Thus, [Ni(CN) 4 ] shows dsp hybridizatio ad square plaar shape. Magetic momet = 0 (as upaired electros are zero).. The hybridizatio state of the cetral atom of complex (A) ad (B) are (a) both are dsp (b) both are sp (c) sp, dsp (d) dsp, sp CN CN Ni Ni CN CN (d) Passage II dsp sp Reactio of Tolle s reaget with glucose Ag e Ag; E o red = V C 6 H 1 6 H C6H 1 7 H e ; E o oxidatio = 0.05 V Ag (NH ; ) e Ag NH E o V red = RT F Give: = & = 8. 5 F RT 4. The value of l K for Ag C 6 H 1 6 H Ag C 6 H 1 7 H is (a) (b) 9.19 (c) 66. (d) Ag e Ag; E o red = V C 6 H 1 6 H C6H 1 7 H e ; E o oxi = 0.05 V Ag (NH ; ) e Ag NH E o V red = 0.7 Ag e Ag; ΔG o 1 = F(0.8) MMENTUM, 5, Wright Tow, Jabalpur (M.P.), Ph.(0761) , 40541

8 IIT JEE 006 C 6 H 1 6 H C6H 1 7 H e ; ΔG o 1 = 1F(0.05) Ag C 6 H 1 6 H Ag C6H 1 7 H ; ΔG =? ΔG = 1.6 F 0.05 F ΔG = 1.55 F ΔG = RT l K RT l K = 1.55 F 1.55 F l K = RT l K = = If o additio of NH, ph of solutio rises to 11. The which of the electrode is affected by chage i ph. (a) E oxidatio icreases over E by 0.65 V (b) E reductio icreases over E by 0.65 V (c) E oxidatio decreases over E by 0.65 V (d) E reductio decreases over E by 0.65 V The aode is affected by chage i ph [C6H1 6 ] E = E log [H ] [C H ] E = E log [H ] = E log [10 11 ] = E = E For this reactio we prefer to add NH, what is the reaso? (a) Ag (NH ) is weaker oxidizig aget tha Ag (b) If we do ot add NH the silver salt of glucoic acid is formed. (c) glucoic acid is soluble i NH (d) to icreases oxidatio potetial of glucose. (b) PassageIII C 14 radio carbo datig techique is used to determie the age of fossil fuel from archaeological excavatios. This techique is based o simple priciple of chemical kietics. Earth s atmosphere is costatly bombarded by cosmic rays (cosistig of electros, eutros ad atomic uclei) of extremely high peetratig power. Atmospheric itroge (N 14 ) captures these eutros (cosmic rays) to produce radioactive C 14 isotope ad hydroge ( 1 H 1 ). 7N 14 o 1 6C 14 1 H 1 The ustable carbo evetually forms 14 C, which mixes with the ordiary carbo dioxide ( 1 C ) i the air. As the carbo14 isotope decays, it emits βparticles. 6C 14 7 N 14 1 β The C 14 isotope eters the biosphere whe carbo dioxide is take up i plat photosythesis. Plats are eate by aimals, which exhale C 14 as C. Evetually, C 14 participates i may aspects of the carbo cycle. The C 14 lost by radioactive decay is costatly repleished by the productio of ew isotopes i the atmosphere. I this decayrepleishmet process, a dyamic equilibrium is established whereby the ratio of C 14 to C 1 remais costat i livig matter. But whe a idividual plat or a aimal dies, the C 14 isotope i it is o loger repleished, so the ratio MMENTUM, 5, Wright Tow, Jabalpur (M.P.), Ph.(0761) , 40541

9 IIT JEE 006 decreases as C 14 decays. So, the umber of C 14 uclei after time t (after the death of livig matter) would be less tha i a livig matter. Now, usig first order itegrated rate law, 0.69 t 1/ = λ For 0,000 year the cosmic rays have same itesity ad orgaism are also have the same. But from some years the chages i this are observed due to excessive burig of fossil fuel ad uclear tests. 7. Why we use the carbo datig to calculate the age of the fossil? (a) Rate of exchage of carbo betwee atmosphere ad livig is slower tha decay of C 14. (b) It is ot appropriate to use C 14 datig to determie age. (c) Rate of exchage of C 14 betwee atmosphere ad leavig orgaism is so fast that a equilibrium is set up betwee the itake of C 14 by orgaism ad its expoetial decay. (d) oe of the above (c) 8. For how may old fossil ca be process of Cdatig be used. (a) 6 years (b) 6000 year (c) 60,000 year (d) ay age it does deped o the age of the fossil. (b) 9. If C 1 is the coc. of C 14 i the sample take ear uclear site ad C is the cocetratio of the sample take away from uclear site 1 C1 (a) t 1 t = l (there is a decrease i age of sample take at uclear site) λ C 1 C1 (b) t 1 t = l (there is a icrease i age of sample take at uclear site) λ C (c) There is o chage irrespective of value of C 1 ad C t1 C1 (d) = t C (b) Passage IV Hoffma Bromamide reactio: C NH C NHBr C N Br N = C = (I) (II) (III ) (IV) NH NC M (V) MMENTUM, 5, Wright Tow, Jabalpur (M.P.), Ph.(0761) , 40541

10 IIT JEE Reaget used i reactio (I) is (a) Br NaH (b) KBr NaH (c) NBS (d) KBr NaHC (a) 1. Which step is r.d.s. for Hoffma Bromamide reactio? (a) (II) (b) (III) (c) (IV) (d) (V) The r.d.s. is formatio of isocyaate i.e. step (III). C N Br C N N = C = NH Br 1, shift Itramolecular H H /. C NH ad The above mixture is treated i above process, the products obtaied are (a) (b) (c) NH NH NH C NH NH NH NH NH NH NH (d) Rearragemet of itree to isocyaate is itramolecular 1,shift. NH C NH NH C NH NH MMENTUM, 5, Wright Tow, Jabalpur (M.P.), Ph.(0761) , 40541

11 IIT JEE g of pheol is dissolved i 1 kg of a solvet (k f = 14) which leads to dimerizatio of pheol ad freezig poit is lowered by 7 kelvi. What percet of total pheol is preset i dimeric form? C 6 H 5 H (C 6 H 5 H) 1 0 1α α/ ΔT f = i k f m = i m = 14 m 1 94 i = α i = 1 α = α 1 i = 1 α α = (1 i) =(1 0.65) α = % pheol is preset i dimeric form. 4. A metal of atomic mass = 75 forms a cubic lattice of edge legth 5 Å ad desity g cm. Calculate the radius of the atom give Avogadro s umber, N A = Zm d = N A a d N A a Z = = m 75 Therefore the cubic lattice will be body cetered. For BCC lattice: a = 4r r = a = 4 5. For the reactio, = = = = pm C(g) (g) C(g); ΔH = 560 kj mol 1 I oe litre vessel at 500 K the iitial pressure is 70 atm ad after the reactio it becomes 40 atm at costat volume of oe litre. Calculate chage is iteral eergy. All the above gases show sigificat deviatio from ideal behaviour. (1 L atm = 0.1 kj) C C; ΔH = 560 kj mol 1 ΔH = ΔU Δ g RT, ΔH = ΔU Δ(PV), ΔH = ΔU V(P P 1 ) 560 = ΔU 1 (4070) 560 = ΔU 0 ΔU = 50 litre atm, ΔU = 5 kj mol 1 6. Questio ot available. List1 List MMENTUM, 5, Wright Tow, Jabalpur (M.P.), Ph.(0761) , 40541

12 IIT JEE (a) Bi [Bi] (P) Hydrolysis (b) Al Al(H) (Q) Acidificatio (c) Si 4 Si 7 (R) ilutio with water (d) B4 7 B(H) (S) heatig P Q R S (b) Q (a) P R S (c) P Q R S (d) P Q R S 8. List-1 List- (a) PhCHCH show fast elimiatio ad (P) E 1 Br PhCCH Br coditio. show slow elimiatio uder the same (b) I PhCH CH Br ad PhC CH Br the later does ot udergoes elimiatio readily. (Q) E 1CB (c) PhCHCH Br o elimiatio i the presece of (R) First order reactio C H 5 ad C H 5 gives PhC = CH (d) Elimiatio i CH CHBrCH is easily as compared to CH CHBrC (S) E (a) P Q R S (b) P Q R S (c) P Q R S (d) P Q R S List1 List 9. (a) Self reductio (P) Pb extractio (b) Carbo reductio (Q) Cu extractio (c) Complex formatio (R) Ag extractio the precipitatio with aother metal (d) decompositio of iodide (S) B extractio (a) P Q R S (b) P Q R S (c) P Q R S (d) P Q R S 40. Give i hydrogeic atom r, V, E, K stad for radius, potetial eergy, total eergy ad kietic eergy i th orbit. Fid the value of U,v,x,y V (a) U = K (P) 1 x (b) E r (Q) y r Z (R) 1 (c) (Z = Atomic umber) (d) v = (Agular mometum of electro (S) 0 i its lowest eergy level) MMENTUM, 5, Wright Tow, Jabalpur (M.P.), Ph.(0761) , 40541

13 IIT JEE 006 V kze / r (a) U = = = K kze / r kz (b) E =, k' r = z, 1 E x = 1 r z (c) r k z 1 r z y = 1 (d) Agular mometum of electro i 1s orbital = h h l (l 1) = 0 (0 1) = 0 π π (a) P Q R S (b) P Q R S (c) P Q R S (d) P Q R S MMENTUM, 5, Wright Tow, Jabalpur (M.P.), Ph.(0761) , 40541

Review Sheet for Final Exam

Review Sheet for Final Exam Sheet for ial To study for the exam, we suggest you look through the past review sheets, exams ad homework assigmets, ad idetify the topics that you most eed to work o. To help with this, the table give