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CBSE Class 12 Board Exam 2020 : Chemistry (Series 2)

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H$moS> Z . Code No. amob Z . 56/2/1 narjmWu H$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. (I) ZmoQ> H $n`m Om M H$a b| {H$ Bg Z-n _o _w{ V n > 19 h & (II) 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| & (III) H $n`m Om M H$a b| {H$ Bg Z-n _| >37 Z h & H $n`m Z H$m C ma {bIZm ew $ H$aZo go nhbo, C ma-nwp VH$m _| 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 & (IV) (V) NOTE (I) Please check that this question paper contains 19 printed pages. (II) 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. (III) Please check that this question paper contains 37 questions. (IV) Please write down the Serial Number of the question in the answer-book before attempting it. (V) 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 .56/2/1 Maximum Marks : 70 1 P.T.O. gm_m ` {ZX}e : {Z Z{b{IV {ZX}em| H$mo ~h V gmdYmZr go n{ T>E Am a CZH$m g Vr go nmbZ H$s{OE : (i) `h Z-n Mma I S>m| _| {d^m{OV {H$`m J`m h H$, I, J Ed K & Bg Z-n _| 37 Z h & g^r Z A{Zdm` h & (ii) I S> H$ _| Z g `m 1 go 20 VH$ A{V bKw-C mar` H$ma Ho$ Z h , `oH$ Z 1 A H$ H$m h & `oH$ Z H$m C ma EH$ e X `m EH$ dm ` _| Xr{OE & (iii) I S> I _| Z g `m 21 go 27 VH$ bKw-C mar` H$ma Ho$ Z h , `oH$ Z 2 A H$m| H$m h & (iv) I S> J _| Z g `m 28 go 34 VH$ XrK -C mar` H$ma-I Ho$ Z h , `oH$ Z 3 A H$m| H$m h & (v) I S> K _| Z g `m 35 go 37 VH$ XrK -C mar` H$ma-II Ho$ Z h , `oH$ Z 5 A H$m| H$m h & (vi) Z-n _| H$moB g_J {dH$ n Zht h & VWm{n, Xmo-Xmo A H$m| Ho$ Xmo Zm| _|, VrZ-VrZ A H$m| Hoo$ Xmo Zm| _| VWm nm M-nm M A H$m| Ho$ VrZm| Zm| _| Am V[aH$ {dH$ n {X`m J`m h & Eogo Zm| _| go Ho$db EH$ hr {dH$ n H$m C ma Xr{OE & (vii) BgHo$ A{V[a $, Amd `H$VmZwgma, `oH$ I S> Am a Z Ho$ gmW `Wmo{MV {ZX}e {XE JE h & (viii) Ho$ Hw$boQ>a AWdm bm J Q>o~b Ho$ `moJ H$s AZw_{V Zht h & I S> H$ {XE JE AZw N>oX H$mo n{ T>E VWm Z g `m 1 go 5 Ho$ C ma Xr{OE : 1. 2. 3. 4. 5. 1 5=5 ~b H$ma Ho$ m {JH$ O go Eo rZmo A b, hm m}Z, V { H$m-g MmaH$, S>r.EZ.E., Eo Ho$bm BS>, a OH$ Am{X | Eo rZ A{^bjH$s` g yh dmbo H$m~ {ZH$ m {JH$ Cnp WV hmoVo h & Am fY {OZH$m mZdm| na eara{H $ m H$ ^md hmoVm h O go {ZH$moQ>rZ, m $s Z, H$moS>rZ Ed hramoBZ, Am{X | ^r Eo rZmo g yh {H$gr Z {H$gr $n | hmoVm h & ZmBQ >moOZ na EH$mH$s Bbo Q >m Z w H$s Cnp W{V Ho$ H$maU Eo rZ jmaH$s hmoVo h & H$m~ {ZH$ T>m Mo | ZmBQ >moOZ H$m moJ Eo rZ Am a Eo mBS> AUwAm| Ho$ Xmo dJm] H$m {Z m U H$aVm h & agm Z {dkmZ Ho$ N>m hmoZo Ho$ ZmVo, h | ZmBQ >moOZ H$s gd Vmo wIr H ${V H$s gamhZm H$aZr Mm{hE & Eo_rZmo A b `m h ? Eo rZmo A b C^ Y u m| hmoVo h ? A br Am a jmaH$s Eo rZmo A b | EH$ A Va Xr{OE & Amd H$ Eo rZmo A b m h ? O~ EH$ Eo rZmo A b H$m H$m~m}p gb {gam X gao Eo rZmo A b Ho$ Eo rZmo {gao Ho$ gmW g K{ZV hmoVm h Vmo ~ZZo dmbo Am~ Y H$m Zm {b{IE & .56/2/1 2 General Instructions : Read the following instructions very carefully and strictly follow them : (i) (ii) (iii) (iv) (v) (vi) (vii) This question paper comprises four Sections A, B, C and D. There are 37 questions in the question paper. All questions are compulsory. Section A Questions no. 1 to 20 are very short answer type questions, carrying 1 mark each. Answer these questions in one word or one sentence. Section B Questions no. 21 to 27 are short answer type questions, carrying 2 marks each. Section C Questions no. 28 to 34 are long answer type-I questions, carrying 3 marks each. Section D Questions no. 35 to 37 are long answer type-II questions, carrying 5 marks each. There is no overall choice in the question paper. However, an internal choice has been provided in 2 questions of two marks, 2 questions of three marks and all the 3 questions of five marks. You have to attempt only one of the choices in such questions. In addition to this, separate instructions are given with each section and question, wherever necessary. (viii) Use of calculators and log tables is not permitted. SECTION A Read the given passage and answer the questions number 1 to 5 that follow : 1 5=5 Organic compounds containing amine as functional group are present in a vivid variety of compounds, namely amino acids, hormones, neurotransmitters, DNA, alkaloids, dyes, etc. Drugs including nicotine, morphine, codeine and heroin, etc. which have physiological effects on humans also contain amino group in one form or another. Amines are basic because of the presence of lone pair of electrons on nitrogen. Addition of nitrogen into an organic framework leads to the formation of two families of molecules, namely amines and amides. As chemistry students, we must appreciate the versatility of nitrogen. 1. What are amino acids ? 2. Why are amino acids amphoteric ? 3. Give one point of difference between acidic and basic amino acid. 4. What are essential amino acids ? 5. Name the linkage formed when carboxyl end of one amino acid condenses with amino end of other amino acid. .56/2/1 3 P.T.O. Z g `m 6 go 10 EH$ e X C mar h : 1 5=5 6. {X A H$ {H$gr Cn w V {dbm H$ | {dbo hmo, Vmo CgHo$ g OrH$aU | w V H $ H$m Zm {b{IE & 7. {H$gr EH$ YmVw H$m CXmhaU Xr{OE {OgH$m emoYZ AmgdZ {d{Y mam {H$ m Om gHo$ & 8. g Hw$b 9. H$moB H$m~ {ZH$ m {JH$ {g{bH$m Oob H$s gVh na A{Yemo{fV h & H$m~ {ZH$ m {JH$ H$mo {g{bH$m Oob go hQ>mZo Ho$ H $ H$m Zm {b{IE & 10. {H$gr A{^{H $ m H$s Hw$b H$mo{Q> H$m n[aH$bZ H$s{OE {OgHo$ doJ {Z OH$ H$s {Z Z H$ma mJw{ V H$s JB : [Co(NH3)5 NO2]Cl2 mam 3 /2 k[NO] doJ = {H$g H$ma H$s g md dVm Xem B OmVr h 1/ 2 [O 2 ] Z g `m 11 go 15 ~h {dH$ nr Z h : 11. byH$mog 1 5=5 C6H12O6 ( moba mZ : 180 g/ mob) Ho$ AUw Cnp WV h & {db Z H$s gm Vm hmoJr 6 02 1022 (A) (B) (C) (D) 0 1 M 0 2 M 1 0 M 2 0 M ? 50 mL Obr {db Z | 12. {X {H$gr Bbo Q >moS> H$m mZH$ Bbo Q >moS> {d^d ey go A{YH$ hmo, Vmo h {Z H$f {ZH$mb gH$Vo h {H$ BgH$m (A) AnM{ V $n hmBS >moOZ J g H$s VwbZm | A{YH$ Wm r h & (B) Am grH $V $n hmBS >moOZ J g H$s VwbZm | A{YH$ Wm r h & (C) AnM{ V Am a Am grH $V $n g mZ $n go Wm r h & (D) AnM{ V $n hmBS >moOZ J g go H$ Wm r h & 13. Co3+ (na mUw (A) (B) (C) 2 7 3 (D) 5 .56/2/1 H $ m H$ = 27) | Cnp WV Hw$b A wp V Bbo Q >m Zm| H$s g m h 4 Questions number 6 to 10 are one word answers : 1 5=5 6. Name the process used for the benefaction of ores if the ore is soluble in some suitable solvent. 7. Give an example of a metal which can be purified by the process of distillation. 8. What type of isomerism is shown by the complex [Co(NH3)5 NO2] Cl2 ? 9. An organic compound is adsorbed on the surface of silica gel. Name the process of removing the organic compound from silica gel. 10. Calculate the overall order of the reaction whose rate law expression was predicted as : 3 /2 Rate = k[NO] 1/ 2 [O 2 ] . Questions number 11 to 15 are multiple choice questions : 1 5=5 11. 50 mL of an aqueous solution of glucose C6H12O6 (Molar mass : 180 g/mol) contains 6 02 1022 molecules. The concentration of the solution will be (A) 0 1 M (B) 0 2 M (C) 1 0 M (D) 2 0 M 12. If the standard electrode potential of an electrode is greater than zero, then we can infer that its (A) reduced form is more stable compared to hydrogen gas. (B) (C) (D) 13. oxidised form is more stable compared to hydrogen gas. reduced and oxidised forms are equally stable. reduced form is less stable than the hydrogen gas. Total number of unpaired electrons present in Co3+ (Atomic number = 27) is (A) 2 (B) 7 (C) (D) .56/2/1 3 5 5 P.T.O. 14. A VamH$mer m {JH$m| Ho$ {df | JbV H$WZ h (A) do amgm {ZH$ { Q> go A{^{H $ merb h & (B) do A V H$R>moa h & (C) do Ymp dH$ MmbH$Vm ~ZmE aIVo h & (D) CZHo$ JbZm H$ C M hmoVo h & 15. (A) (B) (C) (D) tert- y{Q>b Eo H$mohm b 2,2-S>mB o{Wb monoZm b 2- o{Wb yQ>oZ-2-Am b 3- o{Wb yQ>oZ-3-Am b Z g `m 16 go 20 Ho$ {bE, Xmo H$WZ {XE JE h {OZ_| EH$ H$mo A{^H$WZ (A) VWm X gao H$mo H$maU (R) mam A {H$V {H$`m J`m h & BZ Zm| Ho$ ghr C ma ZrMo {XE JE H$mo S>m| (i), (ii), (iii) Am a (iv) _| go MwZH$a Xr{OE : 1 5=5 (i) (ii) (iii) (iv) 16. A{^H$WZ (A) Am a H$maU (R) XmoZm| ghr H$WZ h Am a H$maU (R), A{^H$WZ (A) H$s ghr m m h & A{^H$WZ (A) Am a H$maU (R) XmoZm| ghr H$WZ h , na Vw H$maU (R), A{^H$WZ (A) H$s ghr m m Zht h & A{^H$WZ (A) ghr h , na Vw H$maU (R) JbV H$WZ h & A{^H$WZ (A) JbV h , na Vw H$maU (R) ghr H$WZ h & A{^H$WZ (A) : Eop H$b h bmBS>m| Ho$ dWZm H$ {Z Z H $ | KQ>Vo h : R-I > R-Br > R-Cl > R-F H$maU (R) : 17. h bmoOZ na mUw Ho$ AmH$ma | d { Ho$ gmW dm S>a dm g ~b KQ>Vo h & A{^H$WZ (A) : {Z Z MH $U MVw $bH$s g Hw$b {dabo hr XoIo OmVo h & H$maU (R) : H$jH$m| H$s {dnmQ>Z D$Om E BVZr A{YH$ Zht hmoVr h Omo w Z Ho$ {bE ~m H$a| & 18. A{^H$WZ (A) : Eo ~y{ Z EH$ Jmo{bH$mH$ma moQ>rZ h & H$maU (R) : nm {bno Q>mBS> H$s m Ibm Hw $S>br ~ZmH$a EH$ grYr m Ibm ~Zm XoVr h & .56/2/1 6 14. The incorrect statement about interstitial compounds is (A) They are chemically reactive. (B) They are very hard. (C) They retain metallic conductivity. (D) They have high melting point. (A) tert-butyl alcohol (B) 2,2-Dimethylpropanol (C) 2-Methylbutan-2-ol (D) 3-Methylbutan-3-ol 15. For questions number 16 to 20, two statements are given one labelled Assertion (A) and the other labelled Reason (R). Select the correct answer to these questions from the codes (i), (ii), (iii) and (iv) as given below : 1 5=5 16. (i) Both assertion (A) and reason (R) are correct statements, and reason (R) is the correct explanation of the assertion (A). (ii) Both assertion (A) and reason (R) are correct statements, but reason (R) is not the correct explanation of the assertion (A). (iii) Assertion (A) is correct, but reason (R) is incorrect statement. (iv) Assertion (A) is incorrect, but reason (R) is correct statement. Assertion (A) : Boiling points of alkyl halides decrease in the order R-I > R-Br > R-Cl > R-F. Reason (R) : 17. Assertion (A) : Low spin tetrahedral complexes are rarely observed. Reason (R) : 18. Van der Waals forces decrease with increase in the size of halogen atom. The orbital splitting energies are not sufficiently large to forcing pairing. Assertion (A) : Albumin is a globular protein. Reason (R) : .56/2/1 Polypeptide chain coils around to give a straight chain. 7 P.T.O. 19. A{^H$WZ (A) : ~ Ho$bmBQ> Vmn T> ~h bH$ h & H$maU (R) : Ja H$aZo na, ~h bH$s m Ibm b ~r Am a grYr m Ibm ~Z OmVr h & 20. A{^H$WZ (A) : p-ZmBQ >mo \$sZm b H$s Anojm o-ZmBQ >mo \$sZm b X ~ b A b h & H$maU (R) : Am VaAmp dH$ (A V:AUwH$) hmBS >moOZ Am~ Y Am Wm} g md d H$mo n am g md d H$s Anojm X ~ b H$a XoVm h & I S> I 21. {Z Z{b{IV Ho$ EH$-EH$ A Va Xr{OE : 1 2=2 (a) em VH$ Am a nr S>mhmar (b) ny{VamoYr Am a {dg H $m r (amoJmUwZmer) AWdm amgm {ZH$ g KQ>Z Ho$ AmYma na YZm Zr Am a G Um Zr An mO H$m| | A Va n Q> H$s{OE & oH$ dJ H$m EH$-EH$ CXmhaU ^r Xr{OE & 2 22. {Z Z{b{IV Ho$ {bE H$maU Xr{OE (a) (b) 23. 24. : 1 2=2 Eo H$mohm b | Am~ Y H$moU MVw $bH$s H$moU go Oam-gm H$ hmoVm h & CH3OH | C OH Am~ Y b ~mB \$sZm b | C OH Am~ Y b ~mB go Oam-gr A{YH$ hmoVr h & {Z Z{b{IV amgm {ZH$ g rH$aUm| H$mo nyU Ed g Vw{bV H$s{OE MnO 4 H2O I (b) MnO 4 H I A{YemofU g Vmnr H$s n[a^mfm {b{IE & {H$gr R>mog A{YemofH$ Ho$ BH$mB mZ mam EH$ {Zp MV Vmn na A{Yemo{fV J g H$s m m Ed Xm~ Ho$ EH$ AmZw^{dH$ g ~ Y Xr{OE & AWdm AmH$ma-daUm H$ C oaU H$mo n[a^m{fV H$s{OE & Cg H $ H$m Zm {b{IE {OgHo$ mam Eo H$mohm bm| H$mo grYo hr J gmobrZ | n[ad{V V H$a {X m OmVm h Am a {d{^ H$ma Ho$ hmBS >moH$m~ Z ~ZVo h & .56/2/1 2 (a) : 8 2 2 19. Assertion (A) : Bakelite is a thermosetting polymer. Reason (R) : 20. On heating, polymeric chain becomes a long and straight chain. Assertion (A) : o-nitrophenol is a weaker acid than p-nitrophenol. Reason (R) : Intramolecular hydrogen bonding makes ortho isomer weaker than para isomer. SECTION B 21. Give one point of difference between the following : (a) Tranquilizers and Analgesics (b) Antiseptics and Disinfectants OR 1 2=2 Differentiate on the basis of chemical composition between cationic and anionic detergents. Also give one example of each category. 22. Give reasons for the following : (a) Bond angle 2 1 2=2 in alcohol is slightly less than the tetrahedral angle. (b) C OH bond length in CH3OH is slightly more than the C OH bond length in phenol. 23. 24. Complete and balance the following chemical equations : (a) MnO 4 H2O I (b) MnO 4 H I 2 Define adsorption isotherm. Give the empirical relationship between the quantity of gas adsorbed by unit mass of solid absorbent and pressure at a particular temperature. OR 2 Define shape-selective catalysis. Name the process by which alcohols convert directly into gasoline and give a variety of hydrocarbons. .56/2/1 9 2 P.T.O. 25. 26. H$moB A{^{H $ m A{^H$maH$ A Ho$ gmnoj W H$mo{Q> H$s h Am a A{^H$maH$ B Ho$ gmnoj ^r W H$mo{Q> H$s h & doJ {Z Xr{OE & Am gV doJ Am a Vm j{UH$ doJ Ho$ ~rM EH$ A Va ^r Xr{OE & 2 {H$gr {d wV -amgm {ZH$ gob Mg (s) + Ag+ (aq) Ag (s) + Mg2+ (aq) Ho$ {bE gob {Z $nU Xr{OE & {b{IE & 27. 25 C na Cn`w V gob Ho$ {bE Zo Q> g rH$aU ^r 2 {Z Z{b{IV p W{V m| | {db Z | {dbo H$s Ad Wm H$s mJw{ V H$s{OE (a) O~ i EH$ go A{YH$ nm m J m & (b) O~ i EH$ go H$ nm m J m & : 2 I S> J 28. {Z Z{b{IV ~h bH$m| Ho$ EH$bH$m| H$s g aMZmE Xr{OE (a) Q>o bm Z (b) p b Q>b (c) ZmBbm Z-6 : 1 3=3 AWdm {Z Z{b{IV ~h bH$m| Ho$ EH$bH$m| Ho$ Zm {b{IE .56/2/1 10 : 1 3=3 25. A reaction is first order w.r.t. reactant A as well as w.r.t. reactant B. Give the rate law. Also give one point of difference between average rate and instantaneous rate. 26. 2 For an electrochemical cell Mg (s) + Ag+ (aq) Ag (s) + Mg2+ (aq), 27. give the cell representation. Also write the Nernst equation for the above cell at 25 C. 2 Predict the state of the solute in the solution in the following situations : 2 (a) When i is found to be more than one. (b) When i is found to be less than one. SECTION C 28. Give the structures of the monomers of the following polymers : (a) Teflon (b) Glyptal (c) Nylon-6 1 3=3 OR Write the names of monomers of the following polymers : .56/2/1 11 1 3=3 P.T.O. 29. {Z Z{b{IV Ho$ {bE H$maU Xr{OE : 1 3=3 (a) EWoZo rZ H$s VwbZm | Eo{ZbrZ X ~ b jma h & (b) Eo{ZbrZ $sS>ob-H $m Q >g A{^{H $ m X{e V Zht H$aVr & (c) J {~ Eb W {b mBS> g bofU mam Ho$db Eo{b ${Q>H$ mW{ H$ Eo rZm| H$m {daMZ {H$ m Om gH$Vm h & 30. {Z Z{b{IV m {JH$m| Ho$ oH$ g w M H$mo nyN>o JE {d WmnZ H$s A{^{H $ merbVm Ho$ Amamohr H $ | dp WV H$s{OE Am a H$maU XoVo h E C ma H$s nw{ > H$s{OE 31. (a) 1-~ mo mo yQ>oZ, 2-~ mo mo yQ>oZ, 2-~ mo mo-2- o{Wb monoZ (SN1 A{^{H $ m) (b) 1-~ mo mo yQ>oZ, 2-~ mo mo yQ>oZ, 2-~ mo mo-2- o{Wb monoZ (SN2 (a) K4[Mn(CN)6] H$m AmB . y.nr.E.gr. Zm VWm na mUw H$m Bbo Q >m {ZH$ {d mg Xr{OE & t2g Am a eg Ho$ [Fe(CN)6]4 (ii) [CoF6]3 (iii) [Ni(CO)4] [ na_mUw H $_m H$ 1 2 2=3 nXm| | Ho$ r YmVw H$sboQ> ^md go m A{^ m h ? EH$ CXmhaU Xr{OE & AWdm {Z Z{b{IV g Hw$bm| Ho$ g H$aU Ed Mw ~H$s dhma {b{IE : (i) 1 A{^{H $ m) (b) 2+1=3 3 : Fe = 26, Co = 27, Ni = 28] 32. ~m gmBQ> go Eobw{ Zm Ho$ {ZjmbZ go g ~ amgm {ZH$ A{^{H $ mE Xr{OE & 33. 2 10 3 M oWoZm BH$ 34. : A b H$s MmbH$Vm 8 10 5 S cm 1 h & {X oWoZm BH$ A b Ho$ {bE H$m mZ 404 S cm2 mol 1 hmo, Vmo BgH$s moba MmbH$Vm Am a {d moOZ m m n[aH${bV H$s{OE & Ob | 31 g E{WbrZ bmBH$m b ( moba mZ = 62 g mol 1) KmobH$a {V{h {db Z ~Zm m J m & {db Z H$m {h m H$ n[aH${bV H$s{OE & (Ob Ho$ {bE Kf = 1 86 K kg mol 1) 3 3 600 g .56/2/1 12 3 29. 30. Account for the following : 1 3=3 (a) Aniline is a weaker base compared to ethanamine. (b) Aniline does not undergo Friedel-Crafts reaction. (c) Only aliphatic primary amines can be prepared by Gabriel Phthalimide synthesis. Justify and arrange the following compounds of each set in increasing order of reactivity towards the asked displacement : 31. 1 1 2=3 2 (a) 1-Bromobutane, 2-Bromobutane, 2-Bromo-2-Methylpropane (SN1 reaction) (b) 1-Bromobutane, 2-Bromobutane, 2-Bromo-2-Methylpropane (SN2 reaction) (a) Give the IUPAC name and electronic configuration of central metal atom in terms of t2g and eg of K4[Mn(CN)6]. (b) What is meant by Chelate effect ? Give an example. OR 2+1=3 Write the hybridisation and magnetic characters of the following complexes : (i) [Fe(CN)6] (ii) [CoF6]3 (iii) [Ni(CO)4] 3 4 [Atomic number : Fe = 26, Co = 27, Ni = 28] 32. 33. Give the chemical reactions involved in the leaching of alumina from bauxite. Conductivity of 2 10 3 M methanoic acid is 8 10 5 S cm 1. Calculate its molar conductivity and degree of dissociation if for methanoic 1 34. 3 acid is 404 S cm2 mol . 3 An antifreeze solution is prepared by dissolving 31 g of ethylene glycol (Molar mass = 62 g mol 1) in 600 g of water. Calculate the freezing point of the solution. (Kf for water = 1 86 K kg mol 1) 3 .56/2/1 13 P.T.O. I S> K 35. (a) (b) {H$gr A{^{H $ m R P Ho$ {bE {dem Zo R H$s gm Vm Ed g Ho$ EH$ J m $ ItMm & Bg J m $ Ho$ AmYma na {Z Z{b{IV Zm| Ho$ C ma Xr{OE : (i) A{^{H $ m H$s H$mo{Q> H$s mJw{ V H$s{OE & (ii) dH $ H$m T>mb m B {JV H$aVm h (iii) doJ p Wam H$ H$s BH$mB m h EH$ W H$mo{Q> H$s A{^{H $ m | t1/2 H$s JUZm H$s{OE & [{X`m J`m h : log 2 = 0 3010, ? ? 25% 1 3=3 {d moOZ hmoZo | 25 { ZQ> bJVo h & 2 log 3 = 0 4771, log 4 = 0 6021] AWdm (a) {H$gr W H$mo{Q> H$s A{^{H $ m Ho$ {bE doJ p Wam H$ AnZr map ^H$ gm Vm go KQ> H$a 1 dm 16 60 s 1 h & A{^H$maH$ H$mo ^mJ ah OmZo | {H$VZm g bJoJm ? 3 (b) {H$gr amgm`{ZH$ A{^{H $ m Ho$ doJ H$mo ^m{dV H$aZo dmbo Xmo H$maH$m| H$mo {b{IE & 1 (c) g K >m| Ho$ ^mdr g K >> hmoZo Ho$ {bE Xmo n[ap W{V m {b{IE & 1 .56/2/1 14 SECTION D 35. (a) (b) Visha plotted a graph between concentration of R and time for a reaction R P. On the basis of this graph, answer the following questions : (i) Predict the order of reaction. (ii) What does the slope of the line indicate ? (iii) What are the units of rate constant ? 1 3=3 A first order reaction takes 25 minutes for 25% decomposition. Calculate t1/2. 2 [Given : log 2 = 0 3010, log 3 = 0 4771, log 4 = 0 6021] OR (a) The rate constant for a first order reaction is 60 s 1. How much time will it take to reduce the initial concentration of the reactant 1 th to its value ? 16 3 (b) Write two factors that affect the rate of a chemical reaction. 1 (c) Write two conditions for the collisions to be effective collisions. 1 .56/2/1 15 P.T.O. 36. {H$arQ>mH$ma g aMZm dmbm H$moB A{H $ Q>br R>mog A dm w | ObH$a J g B ~ZmVm h Omo MyZo Ho$ nmZr H$mo X {Y m H$a XoVr h & g $mBS> A H$m| Ho$ ^O Z go ^r B C nm{XV hmoVr h & V2O5 H$s Cnp W{V | B Am grH $V hmoH$a C XoVr h VWm C H$s C M bp Y Ho$ {bE H$ Vmn Am a C M Xm~ Cn w V p W{V m h & C , H2SO4 | Ademo{fV hmoH$a D XoVr h & V n MmV D H$m VZwH$aU H$aZo na A {YH$ h dnyU m {JH$ E m V hmoVm h & C moJ | E {d{^ m {JH$m| Ho$ {Z m U Ho$ {bE `mnH$ $n go C maXm r h & E gm Ad Wm | Cu YmVw go A{^{H $ m H$aHo$ m {JH$ F XoVm h & Bg dU Z go (a) A go F H$s (b) E Ho$ F | (c) 1 g aMZmE n Q> H$s{OE & 2 n[adV Z Ho$ {bE g Vw{bV amgm {ZH$ g rH$aU {b{IE & E Ho$ CZ Xmo h dnyU H$m m] H$mo {b{IE {OZH$s amgm {ZH$ C moJ | ^y{ H$m hmoVr 1 h & (a) (b) 6=3 AWdm {Z Z{b{IV ojUm| Ho$ {bE H$maU Xr{OE 2 : (i) h bmoOZ ~b Am grH$maH$ h & (ii) C H $ Q> J gm| Ho$ dWZm H$ A {YH$ {Z Z hmoVo h & (iii) O (i) NaOH + Cl2 1 2=1 1 3=3 Am a Cl H$s {d wV -G$Um H$Vm bJ^J EH$ g mZ hmoVr h { $a ^r Am grOZ H Am~ Y ~ZmVm h O~{H$ Cl Zht & {Z Z{b{IV amgm {ZH$ g rH$aUm| H$mo nyU Ed g Vw{bV H$s{OE : 1 2=2 (R> S>m VWm VZw) (ii) 37. I (aq) + H2O (l) + O3 (g) (a) EH$ H$m~ {ZH$ m {JH$ A {OgH$m Amp dH$ gy C5H10O h , G$Um H$ Q>m bo g narjU XoVm h , br o gZ AnM Z go n-no Q>oZ ~ZmVm h na Vw Am moS>mo $m narjU Zht XoVm & A H$s nhMmZ H$s{OE VWm g^r g ~ A{^{H $ mE Xr{OE & 1+1=2 (b) {Z Z{b{IV $nm VaU g n H$s{OE : (i) monoZm BH$ A b go 2-~ mo mo monoZm BH$ A b (ii) .56/2/1 ~o Om b bmoamBS> go ~o Op S>hmBS> 16 1 2=2 36. An amorphous solid A which has a crown shaped structure, burns in air to form a gas B which turns lime water milky. B is also produced by roasting of sulphide ores. B undergoes oxidation in the presence of V 2O5 to give C and to carry out this oxidation low temperature and high pressure is mandatory to get a good yield of C . C is then absorbed in H2SO4 to give D . D is then diluted to give a very important compound E . E is largely responsible for the manufacture of variety of compounds in industry. E in concentrated form, when combined with Cu metal, gives compound F . From this description (a) Elucidate the structure of A to F . (b) Give a balanced chemical equation for the conversion of E to F . (c) Give two important functions of E in the chemical industry. OR (a) (b) 37. (a) Give reasons for the following observations : 1 2 6=3 1 1 2 2=1 1 3=3 (i) Halogens are strong oxidising agents. (ii) Noble gases have very low boiling points. (iii) O and Cl have nearly same electronegativity, yet oxygen forms H bond while Cl doesn t. Complete and balance the following chemical equations : (i) NaOH + Cl2 (cold + dil.) (ii) I (aq) + H2O (l) + O3 (g) 1 2=2 An organic compound A having molecular formula C5H10O gives negative Tollens test, forms n-pentane on Clemmensen reduction but doesn t give iodoform test. Identify A and give all the reactions involved. 1+1=2 (b) Carry out the following conversions : (i) Propanoic acid to 2-Bromopropanoic acid (ii) .56/2/1 1 2=2 Benzoyl chloride to benzaldehyde 17 P.T.O. (c) Amn ~o O p S>hmBS> Am a EogrQ> p S>hmBS> Ho$ ~rM H $go {d^oX H$a|Jo ? 1 AWdm (a) (b) .56/2/1 {Z Z{b{IV A{^{H $ mAm| Ho$ AZwH $ H$mo nyU H$s{OE (i) (A) go (D) H$s (ii) (A) H$m : 1 nhMmZ H$s{OE & 2 4=2 AmB . y.nr.E.gr. Zm {b{IE & Amn (i) EWoZm b Am a monoZmoZ, VWm {d^oX H$a|Jo ? (ii) 18 1 ~o Om BH$ A b Am a \$sZm b Ho$ ~rM H $go 2 (c) (a) (b) .56/2/1 How will you distinguish acetaldehyde ? OR between benzaldehyde and 1 Complete the following sequence of reactions : 1 (i) Identify (A) to (D). (ii) Give the IUPAC name of (A). 2 How can you distinguish between : (i) Ethanol and Propanone, and (ii) Benzoic acid and Phenol ? 19 4=2 1 2 P.T.O.

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