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CBSE Class 12 Board Exam 2018 : Chemistry

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SET-1 H$moS> Z . Series SGN Code No. amob Z . 56/1 narjmWu H$moS >H$mo C ma-nwp VH$m Ho$ _wI-n >na Ad ` {bIo & Roll No. Candidates must write the Code on the title page of the answer-book. H $n`m Om M H$a b| {H$ Bg Z-n _o _w{ V n > 15 h & Z-n _| Xm{hZo hmW H$s Amoa {XE JE H$moS >Z ~a H$mo N>m C ma -nwp VH$m Ho$ _wI-n > na {bI| & H $n`m Om M H$a b| {H$ Bg Z-n _| >26 Z h & H $n`m Z H$m C ma {bIZm ew $ H$aZo go nhbo, Z H$m H $_m H$ Ad ` {bI| & Bg Z-n H$mo n T>Zo Ho$ {bE 15 {_ZQ >H$m g_` {X`m J`m h & Z-n H$m {dVaU nydm _| 10.15 ~Oo {H$`m OmEJm & 10.15 ~Oo go 10.30 ~Oo VH$ N>m Ho$db Z-n H$mo n T>|Jo Am a Bg Ad{Y Ho$ Xm amZ do C ma-nwp VH$m na H$moB C ma Zht {bI|Jo & Please check that this question paper contains 15 printed pages. Code number given on the right hand side of the question paper should be written on the title page of the answer-book by the candidate. Please check that this question paper contains 26 questions. Please write down the Serial Number of the question before attempting it. 15 minute time has been allotted to read this question paper. The question paper will be distributed at 10.15 a.m. From 10.15 a.m. to 10.30 a.m., the students will read the question paper only and will not write any answer on the answer-book during this period. agm`Z {dkmZ (g mp VH$) CHEMISTRY (Theory) {ZYm [aV g_` : 3 K Q>o A{YH$V_ A H$ : 70 Time allowed : 3 hours 56/1 Maximum Marks : 70 1 P.T.O. gm_m ` {ZX}e : (i) g^r Z A{Zdm` h & (ii) Z g `m 1 go 5 VH$ A{V bKw-C mar` Z h Am a `oH$ Z Ho$ {bE 1 A H$ h & (iii) Z g `m 6 go 10 VH$ bKw-C mar` Z h Am a `oH$ Z Ho$ {bE 2 A H$ h & (iv) Z g `m 11 go 22 VH$ ^r bKw-C mar` Z h Am a `oH$ Z Ho$ {bE 3 A H$ h & (v) Z g `m 23 _y `mYm[aV Z h Am a BgHo$ {bE 4 A H$ h & (vi) Z g `m 24 go 26 VH$ XrK -C mar` Z h Am a `oH$ Z Ho$ {bE 5 A H$ h & (vii) `{X Amd `H$Vm hmo, Vmo bm J Q>o~bm| H$m `moJ H$a| & H $ Hw$boQ>am| Ho$ Cn`moJ H$s AZw_{V Zht h & General Instructions : (i) All questions are compulsory. (ii) Questions number 1 to 5 are very short answer questions and carry 1 mark each. (iii) Questions number 6 to 10 are short answer questions and carry 2 marks each. (iv) Questions number 11 to 22 are also short answer questions and carry 3 marks each. (v) Question number 23 is a value based question and carries 4 marks. (vi) Questions number 24 to 26 are long answer questions and carry 5 marks each. (vii) Use log tables, if necessary. Use of calculators is not allowed. 1. FeO H$m {d bofU Xem Vm h {H$ BgH$m hmoVm h & H$maU Xr{OE & Fe0 95O gy g{hV Zm Z- Q>m B{H$`mo_rQ >r g KQ>Z 1 Analysis shows that FeO has a non-stoichiometric composition with formula Fe0 95O. Give reason. 2. CO (g) Am a H2 (g) {^ C oaH$m| H$s Cnp W{V _| A{^{H $`m H$aHo$ {^ -{^ C nmX XoVo h & BZ A{^{H $`mAm| mam C oaH$ H$s H$m Z-gr j_Vm X{e V hmoVr h ? CO (g) and H2 (g) react to give different products in the presence of different catalysts. Which ability of the catalyst is shown by these reactions ? 56/1 2 1 3. g Hw$b [Pt(en)2Cl2] _| b {Q>Z_ H$s Cnghg `moOZ g `m Am a Am grH$aU Ad Wm {b{IE & 1 Write the coordination number and oxidation state of Platinum in the complex [Pt(en)2Cl2]. 4. bmoamo~o OrZ Am a ~op Ob bmoamBS> _| go H$m Z-gm Obr` Ob-AnK{Q>V hmo OmVm h Am a `m| ? NaOH mam AmgmZr go 1 Out of chlorobenzene and benzyl chloride, which one gets easily hydrolysed by aqueous NaOH and why ? 5. {Z Z{b{IV H$m AmB .`y.nr.E.gr. Zm_ {b{IE : 1 CH3 | CH3 C CH CH3 | | C2H5 OH Write the IUPAC name of the following : CH3 | CH3 C CH CH3 | | C2H5 OH 6. _| 60 g byH$mog (_moba `_mZ = 180 g mol 1) {_bmZo na ~Zo {db`Z H$m {h_m H$ n[aH${bV H$s{OE & (nmZr Ho$ {bE Kf = 1 86 K kg mol 1) 250 g nmZr 2 Calculate the freezing point of a solution containing 60 g of glucose (Molar mass = 180 g mol 1) in 250 g of water. (Kf of water = 1 86 K kg mol 1) 7. A{^{H $`m 2N2O5 (g) 4NO2 (g) + O2 (g) Ho$ {bE NO2 (g) Ho$ {Z_m U ({daMZ) H$s Xa 2 8 10 3 M s 1 h & N2O5 (g) Ho$ {dbmonZ H$s Xa H$m n[aH$bZ H$s{OE & 2 For the reaction 2N2O5 (g) 4NO2 (g) + O2 (g), the rate of formation of NO2 (g) is 2 8 10 3 M s 1. Calculate the rate of disappearance of N2O5 (g). 56/1 3 P.T.O. 8. dJ -15 Ho$ V dm| Ho$ hmBS >mBS>m| _| go, (a) {H$gH$m {Z ZV_ dWZm H$ hmoVm h 2 ? (b) {H$gH$s A{YH$V_ jmaH$s` H ${V hmoVr h (c) {H$gH$m C V_ Am~ Y H$moU hmoVm h (d) {H$gH$s A{YH$V_ AnMm`r H ${V hmoVr h ? ? ? Among the hydrides of Group-15 elements, which have the 9. (a) lowest boiling point ? (b) maximum basic character ? (c) highest bond angle ? (d) maximum reducing character ? Amn {Z Z{b{IV H$m $nm VaU H $go H$aVo h (a) EWoZ b H$mo monoZm Z _| (b) Q>m byB Z H$mo ~o OmoBH$ A b _| ? 2 AWdm {Z Z{b{IV Ho$ {bE H$maU Xr{OE : 2 (a) Eoamo_o{Q>H$ H$m~m}p g{bH$ A b \ $sS>ob-H $m Q >g A{^{H $`m X{e V Zht H$aVo h & (b) 4-ZmBQ >mo~o OmoBH$ A b H$m pKa _mZ ~o OmoBH$ A b Ho$ pKa _mZ go H$_ hmoVm h & How do you convert the following ? (a) Ethanal to Propanone (b) Toluene to Benzoic acid OR Account for the following : 56/1 (a) Aromatic carboxylic acids do not undergo Friedel-Crafts reaction. (b) pKa value of 4-nitrobenzoic acid is lower than that of benzoic acid. 4 10. {Z Z{b{IV amgm`{ZH$ g_rH$aUm| H$mo nyU Ed g Vw{bV H$s{OE (a) Fe2+ + MnO 4 + H+ (b) MnO 4 + H2O + I : 2 Complete and balance the following chemical equations : 11. (a) Fe2+ + MnO 4 + H+ (b) MnO 4 + H2O + I {Z Z{b{IV Ho$ {bE H$maU Xr{OE : (a) moQ>rZm| Am a ~h bH$m| O go ~ hXmUwAm| Ho$ _moba `_mZ kmV H$aZo Ho$ {bE namgaU Xm~ _mnZ {d{Y H$mo dar`Vm Xr OmVr h & (b) Obr` O VwAm| Ho$ {bE J_ Ob H$s VwbZm _| R> S>o Ob _| ahZm A{YH$ Amam_Xm`H$ hmoVm h & (c) 1 M KCl {db`Z H$m dWZm H$ C `Z bJ^J X JwZm hmoVm h & 1 M eH $am 3 {db`Z Ho$ dWZm H$ C `Z go Give reasons for the following : 12. (a) Measurement of osmotic pressure method is preferred for the determination of molar masses of macromolecules such as proteins and polymers. (b) Aquatic animals are more comfortable in cold water than in warm water. (c) Elevation of boiling point of 1 M KCl solution is nearly double than that of 1 M sugar solution. \$bH$-Ho$p V KZr` (f.c.c.) g aMZm dmbo EH$ V d X (na_mUw `_mZ = 40 g mol 1) Ho$ EH$H$ H$mo{ >H$m H$moa H$s b ~mB 400 pm h & X Ho$ 4 g _| Cnp WV EH$H$ H$mop R>H$mAm| H$s g `m VWm X H$m KZ d n[aH${bV H$s{OE & (NA = 6 022 1023 mol 1) 3 An element X (At. mass = 40 g mol 1) having f.c.c. structure, has unit cell edge length of 400 pm. Calculate the density of X and the number of unit cells in 4 g of X . (NA = 6 022 1023 mol 1) 56/1 5 P.T.O. 13. {H$gr W_ H$mo{Q> H$s A{^{H $`m H$mo 50% nyU hmoZo Ho$ {bE 300 K na 40 {_ZQ> bJVo h Am a 320 K na 20 {_ZQ> bJVo h & A{^{H $`m H$s g{H $`U D$Om n[aH${bV H$s{OE & ({X`m J`m h : log 2 = 0 3010, log 4 = 0 6021, R = 8 314 JK 1 mol 1) 3 A first order reaction is 50% completed in 40 minutes at 300 K and in 20 minutes at 320 K. Calculate the activation energy of the reaction. (Given : log 2 = 0 3010, log 4 = 0 6021, R = 8 314 JK 1 mol 1) 14. `m hmoVm h O~ (a) {H$gr Vm Oo ~Zo Fe(OH)3 Ho$ Adjon H$mo gmW {hbm`m OmVm h ? FeCl3 (b) {H$gr H$mobm BS>r {db`Z H$m XrK Wm`r (bJmVma) AnmohZ {H$`m OmVm h (c) {H$gr B_ eZ H$m AnH|$ U {H$`m OmVm h {db`Z H$s Wmo S>r gr _m m Ho$ ? ? 3 What happens when 15. (a) a freshly prepared precipitate of Fe(OH)3 is shaken with a small amount of FeCl3 solution ? (b) persistent dialysis of a colloidal solution is carried out ? (c) an emulsion is centrifuged ? gmoZo Ho$ {Z H$f U Ho$ H $_ go g ~ amgm`{ZH$ A{^{H $`mE {b{IE & Bg H $_ _| VZw NaCN Am a Zn H$s ^y{_H$m H$s `m `m H$s{OE & 3 Write the chemical reactions involved in the process of extraction of Gold. Explain the role of dilute NaCN and Zn in this process. 16. 56/1 H$maU Xr{OE : 3 o (a) Mn3+/ Mn2+ (b) H$m na H$s H$UZ E W nr H$s Anojm Am`aZ H$s H$UZ E W nr C Va hmoVr h & (c) Obr` {db`Z _| `w _ Ho$ {bE YZm _H$ hmoVm h & Sc3+ a JhrZ E H$m _mZ Fe3+/ Fe2+ hmoVm h O~{H$ 6 Ti3+ a JrZ Ho$ _mZ go ~h V A{YH$ & Give reasons : (a) o E value for Mn3+/ Mn2+ couple is much more positive than that for Fe3+/ Fe2+. 17. (b) Iron has higher enthalpy of atomization than that of copper. (c) Sc3+ is colourless in aqueous solution whereas Ti3+ is coloured. (a) {Z Z{b{IV `w _ _| {H$aob AUw H$s nhMmZ H$s{OE (b) gmo{S>`_ YmVw Am a ew H$ B Wa H$s Cnp W{V _| O~ bmoamo~o OrZ H$s _o{Wb bmoamBS> go A{^{H $`m H$s OmVr h , Vmo ~ZZo dmbo C nmX H$s g aMZm {b{IE & 1-~ mo_mo-1-_o{WbgmB bmoho goZ Ho$ Eo H$mohm br KOH mam {dhmBS >moh bmoOZZ go ~ZZo dmbo Eo H$sZ H$s g aMZm {b{IE & (c) 18. 56/1 : (a) Identify the chiral molecule in the following pair : (b) Write the structure of the product when chlorobenzene is treated with methyl chloride in the presence of sodium metal and dry ether. (c) Write the structure of the alkene formed by dehydrohalogenation of 1-bromo-1-methylcyclohexane with alcoholic KOH. Am a (C) Amp dH$ gy C4H8O dmbo {H$gr H$m~m}{Zb `m {JH$ Ho$ VrZ AMH $s` A{^bjH$s g_md`d h & g_md`d (A) Am a (C) gH$mam _H$ Q>m boZ narjU XoVo h O~{H$ g_md`d (B) Q>m boZ narjU Zht XoVm h bo{H$Z gH$mam _H$ Am`moS>mo\$m _ narjU XoVm h & g_md`d (A) Am a (B) Zn(Hg)/gm HCl go AnM{`V hmoH$a g_mZ `m {JH$ (D) XoVo h & (a) (A), (B), (C) Am a (D) H$s g aMZmE {b{IE & (b) g_md`d (A), (B) Am a (C) _| go H$m Z-gm HCN Ho$ g `moOZ Ho$ {V `yZV_ A{^{H $`merb h ? 3 (A), (B) 7 3 P.T.O. (A), (B) and (C) are three non-cyclic functional isomers of a carbonyl compound with molecular formula C4H8O. Isomers (A) and (C) give positive Tollens test whereas isomer (B) does not give Tollens test but gives positive Iodoform test. Isomers (A) and (B) on reduction with Zn(Hg)/conc. HCl give the same product (D). 19. (a) Write the structures of (A), (B), (C) and (D). (b) Out of (A), (B) and (C) isomers, which one is least reactive towards addition of HCN ? {Z Z{b{IV A{^{H $`mAm| _| _w ` C nmXm| H$s g aMZmE {b{IE : Write the structures of the main products in the following reactions : 56/1 8 3 20. (a) (b) (c) ~mBWm`moZ b H$mo gm~wZ _| `m| {_bm`m OmVm h ? Am`moS>rZ H$m qQ> Ma `m h ? BgH$m EH$ Cn`moJ {b{IE & {Z Z{b{IV _| go H$m Z-gm EH$ Im n[aajH$ Ho$ $n _| H$m` H$aVm h Eo nmQ>}_, Eop n[aZ, gmo{S>`_ ~o OmoEQ>, n am{gQ>o_m b ? (a) Why is bithional added to soap ? (b) What is tincture of iodine ? Write its one use. (c) Among the following, which one acts as a food preservative ? 3 Aspartame, Aspirin, Sodium Benzoate, Paracetamol 21. {Z Z{b{IV H$mo EH$-EH$ CXmhaU g{hV n[a^m{fV H$s{OE (a) nm {bg H $amBS> (b) {dH $VrH $V moQ>rZ (c) Amd `H$ Eo_rZmo A b : 3 AWdm (a) (b) (c) D- byH$mog H$s gm ZmB{Q >H$ A b (HNO3) Ho$ gmW A{^{H $`m H$aZo na ~ZZo dmbo C nmX H$mo {b{IE & Eo_rZmo A b C^`Y_u `dhma Xem Vo h & `m| ? moQ>rZm| H$s -ho{b g VWm - brQ>oS> g aMZmAm| _| EH$ A Va {b{IE & 3 Define the following with an example of each : (a) Polysaccharides (b) Denatured protein (c) Essential amino acids OR 56/1 (a) Write the product when D-glucose reacts with conc. HNO3. (b) Amino acids show amphoteric behaviour. Why ? (c) Write one difference between -helix and -pleated structures of proteins. 9 P.T.O. 22. (a) (b) (c) (a) {Z Z{b{IV Cnghg `moOH$ `m {JH$ H$m gy {b{IE : Am`aZ(III) ho gmgm`Zmo\o$aoQ>(II) g Hw$b [Co(NH3)5Cl]SO4 {H$g H$ma H$s g_md`dVm X{e V H$aVm h ? g Hw$b [CoF6]3 _| g H$aU Am a A`wp _V Bbo Q >m Zm| H$s g `m {b{IE & (Co H$m na_mUw H $_m H$ = 27) 3 Write the formula of the following coordination compound : Iron(III) hexacyanoferrate(II) 23. (b) What type of isomerism [Co(NH3)5Cl]SO4 ? is exhibited by the complex (c) Write the hybridisation and number of unpaired electrons in the complex [CoF6]3 . (Atomic No. of Co = 27) Hw$N> Im nXmWm] H$mo H $` H$aZo Ho$ {bE `m_ EH$ n gmar ({H$amZm) H$s X H$mZ na J`m & X H$mZXma Zo g^r nXmWm] H$mo nm {bWrZ Ho$ W bm| _| ^aH$a `m_ H$mo {X`m & bo{H$Z `m_ Zo nm {bWrZ Ho$ W bm| H$mo drH$ma H$aZo go _Zm H$a {X`m VWm X H$mZXma H$mo H$hm {H$ nXmWm] H$mo H$m J O Ho$ W bm| _| ^aH$a {X`m OmE & CgZo X H$mZXma H$mo gy{MV {H$`m {H$ nm {bWrZ Ho$ W bm| Ho$ `moJ na gaH$ma mam ^mar Ow_m Zm bJm`m OmVm h & X H$mZXma Zo ^{d ` _| nm {bWrZ Ho$ W bm| H$s OJh H$m J O Ho$ W bo `moJ H$aZo H$m dmXm {H$`m & {Z Z{b{IV Ho$ C ma Xr{OE : (a) `m_ mam Xem E JE _y `m| (H$_-go-H$_ Xmo) H$mo {b{IE & (b) A n KZ d nm {bWrZ Am a C KZ d nm {bWrZ Ho$ ~rM EH$ g aMZm _H$ A Va {b{IE & (c) `m_ Zo nXmWm] H$mo nm {bWrZ Ho$ W bm| _| boZo go `m| _Zm H$a {X`m ? (d) O d-{Z ZrH$aUr` ~h bH$ `m h ? EH$ CXmhaU Xr{OE & Shyam went to a grocery shop to purchase some food items. The shopkeeper packed all the items in polythene bags and gave them to Shyam. But Shyam refused to accept the polythene bags and asked the shopkeeper to pack the items in paper bags. He informed the shopkeeper about the heavy penalty imposed by the government for using polythene bags. The shopkeeper promised that he would use paper bags in future in place of polythene bags. Answer the following : (a) 56/1 Write the values (at least two) shown by Shyam. 10 4 24. (b) Write one structural difference between low-density polythene and high-density polythene. (c) Why did Shyam refuse to accept the items in polythene bags ? (d) What is a biodegradable polymer ? Give an example. (a) H$maU Xr{OE (b) : (i) H3PO3 Ag_mZwnmVZ (ii) O~ Cl2, F2 Ho$ Am{Y ` Ho$ gmW A{^{H $`m H$aVr h , Vmo {H$ FCl3 & (iii) H$j Vmn na S>mBAm grOZ EH$ J g h O~{H$ g \$a EH$ R>mog h & A{^{H $`m XoVm h na Vw {Z Z{b{IV H$s g aMZmE Amao{IV H$s{OE (i) XeF4 (ii) HClO3 H3PO4 Zht XoVm & ClF3 ~ZVm h Z : 5 AWdm (a) (b) O~ gm g `y[aH$ A b H$mo {H$gr naIZbr _| Cnp WV AkmV bdU na S>mbm J`m Vmo EH$ ^yar J g (A) {ZH$br & Bg naIZbr _| Vm ~o H$s N>rbZ S>mbZo na J g {ZH$bZo H$s Vrd Vm _| d { hmo JB & R> S>m H$aZo na J g (A) EH$ a JhrZ R>mog (B) _| n[ad{V V hmo JB & (i) (A) Am a (B) H$s nhMmZ H$s{OE & (ii) (A) Am a (B) H$s g aMZmE {b{IE & (iii) J g (A) H$mo R> S>m H$aZo na dh R>mog _| `m| n[ad{V V hmo OmVr h ? {Z Z{b{IV H$mo CZHo$ AnMm`H$ bjU Ho$ KQ>Vo h E H $_ _| `dp WV H$s{OE : HF, HCl, HBr, HI (c) {Z Z{b{IV A{^{H $`m H$mo nyU H$s{OE XeF4 + SbF5 56/1 : 5 11 P.T.O. (a) Give reasons : (i) H3PO3 undergoes disproportionation reaction but H3PO4 does not. (ii) When Cl2 reacts with excess of F2, ClF3 is formed and not FCl3. (iii) (b) Dioxygen is a gas while Sulphur is a solid at room temperature. Draw the structures of the following : (i) XeF4 (ii) HClO3 OR (a) When concentrated sulphuric acid was added to an unknown salt present in a test tube a brown gas (A) was evolved. This gas intensified when copper turnings were added to this test tube. On cooling, the gas (A) changed into a colourless solid (B). (i) Identify (A) and (B). (ii) Write the structures of (A) and (B). (iii) Why does gas (A) change to solid on cooling ? (b) Arrange the following in the decreasing order of their reducing character : HF, HCl, HBr, HI (c) Complete the following reaction : XeF4 + SbF5 25. (a) {Z Z{b{IV gob Ho$ {bE gob A{^{H $`m {b{IE Am a (e.m.f.) n[aH${bV H$s{OE : 298 K na {d wV -dmhH$ ~b Sn (s) | Sn2+ (0 004 M) || H+ (0 020 M) | H2 (g) (1 bar) | Pt (s) ({X`m J`m h (b) 56/1 : E o Sn 2 / Sn = 0 14 V) H$maU Xr{OE : o (i) E _mZm| Ho$ AmYma na, Obr` NaCl Ho$ {d wV -AnKQ>Z _| EZmoS> na J g {ZH$bZr Mm{hE na Vw Cl2 J g {ZH$bVr h & (ii) CH3COOH H$s MmbH$Vm VZyH$aU na KQ>Vr h & AWdm 12 O2 5 (a) 25 C na A{^{H $`m 2AgCl (s) + H2 (g) (1 atm) 2Ag (s) + 2H+ (0 1 M) + 2Cl (0 1 M) Ho$ {bE Go = 43600 J h & gob H$m {d wV -dmhH$ ~b (e.m.f.) n[aH${bV H$s{OE & [log 10 n = n] (b) B YZ gob H$mo n[a^m{fV H$s{OE Am a BgHo$ Xmo bm^ {b{IE & 5 (a) Write the cell reaction and calculate the e.m.f. of the following cell at 298 K : Sn (s) | Sn2+ (0 004 M) || H+ (0 020 M) | H2 (g) (1 bar) | Pt (s) (Given : E (b) o Sn 2 / Sn = 0 14 V) Give reasons : o (i) On the basis of E values, O2 gas should be liberated at anode but it is Cl2 gas which is liberated in the electrolysis of aqueous NaCl. (ii) Conductivity of CH3COOH decreases on dilution. OR (a) For the reaction 2AgCl (s) + H2 (g) (1 atm) 2Ag (s) + 2H+ (0 1 M) + 2Cl (0 1 M), o G = 43600 J at 25 C. Calculate the e.m.f. of the cell. [log 10 n = n] 26. 56/1 (b) Define fuel cell and write its two advantages. (a) {Z Z{b{IV go g ~ A{^{H $`mE {b{IE : (i) hm \$_mZ ~ mo_m_mBS> {Z ZrH$aU A{^{H $`m (ii) S>mBEo OmoQ>rH$aU (iii) J {~ `b W {b_mBS> g bofU 13 P.T.O. (b) H$maU Xr{OE : (i) Obr` {db`Z _| hmoVr h & (CH3)3N (ii) Eo{b\ ${Q>H$ S>mBE Omo{Z`_ bdUm| H$s Anojm Eoamo_ {Q>H$ S>mBE Omo{Z`_ bdU A{YH$ Wm`r hmoVo h & 3+2=5 H$s VwbZm _| (CH3)2NH A{YH$ jmaH$s` AWdm (a) {Z Z{b{IV A{^{H $`mAm| Ho$ _w ` C nmXm| H$s g aMZmE {b{IE (b) Eo{ZbrZ Am a N,N-S>mB_o{WbEo{ZbrZ _| {d^oX H$aZo Ho$ {bE EH$ gab amgm`{ZH$ narjU Xr{OE & (c) {Z Z{b{IV H$mo CZHo$ pKb _mZm| Ho$ ~ T>Vo h E H $_ _| `dp WV H$s{OE C6H5NH2, C2H5NH2, C6H5NHCH3 (a) 56/1 : Write the reactions involved in the following : (i) Hofmann bromamide degradation reaction (ii) Diazotisation (iii) Gabriel phthalimide synthesis 14 : 5 (b) Give reasons : (i) (CH3)2NH is more basic than (CH3)3N in an aqueous solution. (ii) Aromatic diazonium salts are more stable than aliphatic diazonium salts. OR (a) Write the structures of the main products of the following reactions : (b) Give a simple chemical test to distinguish between Aniline and N,N-dimethylaniline. (c) Arrange the following in the increasing order of their pKb values : C6H5NH2, C2H5NH2, C6H5NHCH3 56/1 15 P.T.O.

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