I Series SSO I Code N~. 56/3(5)s ';f.

Roll No.W1 ;t.

Candidates must write the Code on

the title page of the answer-book.

tRTaw.IT C!5ls em 3'rR -~~QJI W- ~-~

1:R~~ I

• Please check that this question paper contains 12 printed pages.

• Code number given on the right hand side of the question paper should bewritten on the title page of the answer-book by the candidate.

• Please check that this question paper contains 30 questions.

• Please write down the Serial Number of the question beforeattempting it.

• 15 minutes time has been allotted to read this question paper. Thequestion paper will be distributed at 10.15 a.m. From 10.15 a.m. to10.30 a.m., the student will read the question paper only and will not writeany answer on the answer script during this period.

• ~ ~ Cf){ ~ fcn ~ ~-1:f;f # ~ ~ 12 ~ I

• ~-1:f;f # ~ m~Chl 3ffi ~ ~ ~ ~ Cf?t ~ ~-~f«1chl ~ :rsr-~ 1R fu&

• ~ ~ Cf){ ~ fcn ~ ~-1:f;f # 30 ~ ~ I

• ~ ~ CfiT ~ f(,.~"'1 ~ ~ it ~, ~ CfiT ~ ~ WRi

• ~ ~-1:f;f Cf?t ~ ~ ~ 15 fl:Rc: ctlT ~ m ~ ~I ~-1:f;f ctlT ~ ~ #10.15 ~ fcn<:rr ~ I 10.15 ~ ~ 10.30 ~ ClCfi ~ m ~-1:f;f Cf?t ~ am:

~ ~ ~m ~~-~ 1R cnW ~ -;:r@ ~ I'"

CHEMISTRY (Theory)

~fa"m;J(~)

Time allowed : 3 hours

56/3 1

Maximum Marks: 70

p.T.a.

General Instructions :

(i) All questions are compulsory.

(ii) Marks for each question are indicated against it.

(iii) Questions number 1 to 8 are very short-answer questions andcarry 1mark each.

(iv) Questions number 9 to 18 are short-answer questions and carry2 marks each.

(v) Questions number 19 to 27 are also short-answer questions andcarry 3 marks each.

(vi) Questions number 28 to 30 are long-answer questions and carry5 marks each.

(vii) Use Log Tables, if necessary. Use of calculators is not allowed.

~~:

(i) ff'ift ~ 31f.:r"cff4 $' I

(ii) J[f'irq; ~ ~ ~ 3fcn ~ 7JTJ: $' I

(iii) ~- ~ 1 it 8 (fCfi 3ffrr ~-3r7fp;r ~ ~. I J[f'irq; ~ ~ fC7r!: 1 3fcn ~ I

(iv) ~- ~ 9 it 18 (fCfi (1f{-3r7fp;r ~ ~ I J[f'irq; ~ ~ fC7r!: 2 3fcn ~ I'"

(v) ~- ~ 19 it 27 (fCfi '4T ~-3r7fp;r ~ ~ I J[f'irq; ~ ~ fC7r!: 3 3fcn ~. I

(vi) ~-~ 28 it 30 cfJrf-3r7fp;r~ ~. I ~ ~ ~ fC7r!: 5 3fcn $' I

(vii) 3WH4q,d/rf.f;-{/~"fifrr ~ q:;r m cR I cJ,r::Pc1c:.~} ~ ~ ctt 3R11frr ;rif'" '"

~ I

1. What is the number of atoms in a unit cell of a face-centred cubiccrystal? 1fcnm ~-~ ~ ~ ~ ~ m-r if ~ W1TUT ~ ~ ?..;)

2. What is the 'coagulation' process? 1i~' (coagulation)"5ffii11CFIT mm ~ ?

•

tal Why is red phosphorus less reactive than white phosphorus?~ ~1~~*1 cnl ~ ~ ~1~~*1 cpr rs:h'1I~I1<.1 cp:ff mm ~ ?

~,

6) What is meant by the term 'pyrometallurgy' ?inN_~' it CFIT ~ mm ~?

1

1

56/3 2

5. Write the structural formula of I-phenylpentan-l-one.

1-~H(.14~<i-1-3TR CfiT ~ m- ~ Ie-.

6. Give the IUPAC name of the following compound:

H2C = CH - CH - CH2 - CH2 - CH31

OH

r ... r .r. .. ~ CfiT IUPAC ~ ~

H2C = CH - CH - CH2 - CH2 - CH3·1

OH

1

1

I

/,i7~)',-

8.

What does '6,6' indicate in the name nylon-6,6 ?

~-6,6 ~ if ~ '6,6' 'Cp1T ~ Cfi\(IT * ?

1

1

.~D Complete the following chemical reaction equations :(i) XeF2 + H20 --7

(ii) BH3 + HgC12 --7

r r r. r ~ ~J-;lcp\u~ ciT ~ ~

(i) XeF2 + H20 --7

(iD PH3 + HgC12 --7

10. Complete the following reaction equations :

0(CH3(i) 0 + HI --7

2

2

56/3 3 p.T.a.

~---

--- ------------ . 1I

11. Which one in the following pairs undergoes SN1 substitution reactionfaster and why ? 2

CI rn

(i) /I~ or ~

Cl. Cl(ii) ~ or~

r r r: ~ if it ~ ~-SNI ~ ~:m~"ffiwIT it ~ ~ 31RCFff?

(i)

Cl

/I~Cl

(ii) ~ 3l~ ~Cl

~comPlete the following chemical reaction equations:, (i) MnO~ (aq) + C2O~- (aq) + H+ (aq) ~ .

(ii) Cr2O~- (aq) + Fe2+ (aq) + H+ (aq) -7

r r r r:m~ ~~·iICPo(Y~ cit 1:[Uf ~

(i) MnO~ (aq) + C20~- (aq) + H+ (aq) ~

(ii) Cr20~- (aq) + Fe2+ (aq) + H+ (aq) -7

2

13. Describe the Tole of the following : 2/­/' I_ .. -,""

~ NaCN in the extraction of silver from a silver ore.

(ii) Cryolite in the extraction of aluminium from pure alumina.

r r r ctT ~ CfiT quf;r ~ :

(i) ~ ~ ~ ~ ~ Hl>:h~UI if NaCN ctT I

(ii) ~ Q~I1Ir11 it Q~~H.!.l11 ~ Hl>:h~UI if 9h1.!.l1<1ISc. ~

56/3 4

14. Define the following:

(i) Order of a reaction

(ii) ,Activation energy of a reaction

r r.r._ .. ~ -qft~ ~ :

(i) 31f~ c8W(ii) 31f~ c8 ~r~"jul ~

2

15. What type of cell is a lead storage battery ? Write the anode and thecathode reactions and the overall cell reaction occurring in the use of alead storage battery. 2

OR

Two half cell reactions of an electrochemical cell are given below :

MnO~ (aq) + 8 H+ (aq) + 5 e- -7 Mn2+ (aq) + 4 H20 (l), EO = + 1·51 V

Sn2+ (aq) -7 Sn4+ (aq) + 2 e-, EO = + 0·15 V

Construct the redox equation from the two half cell reactions andpredict if this reaction favours formation of reactants or productshown in the equation. 2

mm ~-ql"jcn ~ fcR:r m CfiT "ffi1, ~ ? mm ~-ql"jcn ~ if m~w:r:r ~

31R ~~ tR ~ Cf!ffi ~ 31R "¥f r~<:1lcn\ ~ 'Cf!ffi "ffi1 ~ ~

~I

3l~

~ ~-\I~I"jHcn ~ ~ ~ 3l~ irc1Tc8 ~ f.:p:;r m ~

MnO~ (aq) + 8 H+ (aq) + 5 e- -7 Mn2+ (aq) + 4 H20 (l), EO = + 1·51 V

Sn2+ ,(aq) -7 Sn4+ (aq) + 2 e-, EO = + 0·15 V

~ ~ itc1 31f~:m it 00cm (~414-q"j)~~lcn\UI R~ ~ 3fR ~

~ fcfi ~ 31f~ ~~lcn\UI ~ 31f~ 3l~ ~ ~ CfiT ~ ~ I'"

16. Name the four bases present in DNA. Which one of these is notpresent in RNA ? 2'qR ~ ~ ~ ~ ~ DNA if fc1'C.l~I..-j ~ I ~ it ~ ~ RNA if ~~ ~ ?

56/3 5 p.T.a.

i/::;"~;

(.!_71 Differentiate between condensation and addition polymerisations. Giveone example each of the resulting polymers. 2

~ q§,(1cnlcn~ul 3fu: <iljll\<-icn q§,(1cnlcn{UI if ~ ~ ~ I ~ ~ c:rr#r ~

m it ~ q:;r~-~ ~c;.IQ{UI ~ I~/--.

?!g~ Name two fat soluble vitamins, their sources and the diseases caused'-- - due to their deficiency in diet. 2

qm if :!c.1•.p{ 11 (1 G) fcR:1f~ it -;w:r, ~ ~ 31R ~ ~ if CfilTI ~ ~ qTffi

:J, .. r. .Ii it -;w:r ~ I

19. Silver crystallises with face-centred cubic unit cells. Each side of theunit cell has a length of 409 pm. What is the radius of an atom ofsilver ? (Assume that each face atom is touching the four corneratoms.) 3~ ~-~ er.:fm ~ iwr if r9h~r(1c1 ~ ~ I ~ iwr it ~ fcfnR cnl

~409pm~ I ~~cnl~CFIT~? (~~~fcn~') ~:qRf ~ it ~3TI ~ m "Cf)\ill ~ I)

20. A first order reaction has a rate constant of 0·0051 min-I. If we beginwith 0·10 M concentration of the reactant, what concentration of thereactant will be left after 3 hours ? 3

~ >f2p1 c8R:- cnl 31f~ q:;r G\ ~ 0·0051 min-1 ~ I ~ ~ ~ it0·10 M ~ it ~~ ~ ~, -ffi 3 ttZ ~ ~ ~ ~ it1f W

~?

21. A voltaic cell is set up at 25° C with the following half-cells:

All A13+ (0·0010 M) and Ni I Ni2+ (0·50 M).

Write the equation for the cell reaction that occurs when the cell

generates an electric current and determine the cell potential.

(Given: EO 2 = - 0·25 V, EO 3 = - 1·66 V) 3Ni +/ Ni AI + / Al

r r r. ~_~All A13+ (0,0010 M) 31R Ni I Ni2+ (0·50 M)

it ~~ ~ ClI<.'"GI~ iwr 25° C ~ ire cnl ~ ~ I ~ iwr ~ ~-mu ~Cfi«IT ~ -ffi ~ cnw iwr ~ it ft;m: ~<-ilcn{ UI ~ 3fu: iwr fcrqq ~

~I

(~ TJ7.IT ~ : EO 2 = - 0·25 V, EO3 = - 1·66 V)Ni +/ Ni AI + / AI

56/3 6

22. What happens in the following activities and why?

(i) An electrolyte is added to a hydrated ferric oxide sol in water.

(ii) A beam of light is passed through a colloidal solution.

(iii) An electric current is passed through a colloidal solution.

r..or or., , M3TI if CF1T ~ ~ 3lR ern ?

(i) 7j[B" if \J1c:1<.iif\J1<1~ 3-lTcffil~s~ if ~ ~-~ ~ ~ ~(ii) ~ ct)c:1T~slfcm<:Rif it wmr $1 ~ m-r ~ ~ I~

/Liii) ~ ct)c:1T~slfcm<:Rif it ~ mu ~ <tt ~ ~ It.-- ..,·::"'/"..... ,/

~/ Explain the following :

(i) Low spin octahedral complexes of nickel are not known.

(ii) The n-complexes are known for transition elements only.

(iii) CO is a stronger ligand than NH3 for many metals.

OR

3

3

Compare the following complexes with respect to structural shapes ofunits, magnetic behaviour and hybrid orbitals involved in units : 3

(i) [Ni(CN)4J2-

(ii) [NiC14J2-

(iii) [CoF 6J3-

[At. Nos. : Ni = 28; Co = 27J-1- L1

r rr itCfiRUT~~:

(i) ~ it .awq ftl:R it 3-l~Lhc:1chl<.!cnT~cffi ~ ~ i(ii) ~ ~ mq) it ~ m n-cnT~q-~ \ifH ~ i I

(iii) ~-m ~3TI it ~. CO fuitug NH3 <tt ~ 31f~ ~ ~3l~

f:ikff~f.(9<1~ (cnT~cffil) <tt "¥AT, ~ ~ <tt ~ 3-l1~~<.!1,.. 0 .'L~ ~ ~cnl~~'if ~ 00 3-lT~C.C1I·it ~ if ~ : 3

(i) [Ni(CN)4J2-

(ii) [NiC14J2-

(iii) [CoF 6J3-

['WJTll] ~ : Ni = 28; Co = 27J

56/3 7 p.T.a.

------,---.-------------I

24. How would you account for the following:

(i) Many of the transition elements and their compounds can act asgood catalysts.

(ii) The metallic radii of the third (5d) series of transition elements

are virtually the same as those of the corresponding members ofthe second series.

(iii) There is a greater range of oxidation states among the actinoidsthan among the lanthanoids.

3:rrq H..., r~r@(f ~ Cf<IT qmur ~ ~ :

(i) ~ -B ~ ~ 3W ~ ~ ~ ~ q)T ~ crut ~

(ii) ~ ~ c€r cmro (5d) ~ ~ ~ c€r ~ ~ ~ cWt mm ~

it ~ ~ ~ d~~4r ~ ctt mm ~ I

(iii) Q~rfl~-51 iT -::$l(-q<?jrf 3=fCW.IT3TIq)T I1m1 ~ c€r .~ 31f~ ~ ~

3

25. Explain the following observations : 3

(i) The boiling point of ethanol is higher than that ofmethoxymethane.

(ii) Phenol is more acidic than ethanol.

(iii) 0- and p-nitrophenols are more acidic than phenol.

r r r. . a:tqc..iich ..i'i c€r ~ ~ :

(i) 11:m q)Tqq~ it~~ ~ qq~ -B ~ ~ ~

(ii) ~ 11:~ it 31f~ .~ ~ ~ I

(iii) 0- 3W p-"'I~~It.h)",Ic1 ~ ~.-B 31f~ ~ ~ ~

26. Complete the following reaction equations :°II LiAlH4

(i) R - C - NH2 H ° )2

(ii) C6HsN2Cl + H3P02 + H20 --7

(iii) C6HsNH2 + Br2 (aq) --7

56/3 8

3

r r r ~ ~1-;lctl-tU~it Tf ~ i: ~°II LiAlH4 .

(i) R - C - NH2 )H20

(ii) C6HSN2Cl + H3P02 + H20 ~

(iii) C6HSNH2 + Br2 (aq) ~

27. What are the following substances? Give one example of each ofthem. 3

(i) Cationic detergents(ii) Enzymes(iii) Sweetening agents

r rr~.\: ~;): ..• ~ ~'iC\I"1 cp:rr (!m (! ( >t\"1q') CfiT ~-~ -:$<;IQ-tUI <..,11\)1'-' I

(i) ~ 31\.j"I~ctl

(ii) l!,~I~.,

(iii) ~GHII (r"dl~ctll-t) • (~)

28. (a) Define the foll{)wingterms:(i) Mole fraction

(ii) Van't Hoff factor

(b) 100 mg of a protein is dissolved in enough water to make10·0 mL of a solution. If this 'solution has an osmotic pressure of13·3 mm Hg at 25° C, what is the molar mass of protein ?(R = ,0·0821 Latm mol-1 K-1 and 760 mm Hg = 1 atm.) 5

OR

(a) What is meant by :

(i) Colligative properties

(ii) Molality of a solution

(b) What concentration of nitrogen should be present in a glass ofwater at room temperature? Assume a temperature of 25° C, atotal pressure of 1 atmosphere and mole fraction of nitrogen inair of 0·78. [KH for nitrogen = 8·42 x 10-7 M/mm Hg] 5

•

56/3 9 P.T.D.

(a) Hkjrc1r~d ~ ~ ~ ~ :

(i) l1Wr am

(ii) CfR ~ ~

(b) ~ mif.:r cn1 100 mg 1WIT ~ ~ ~ if ~ 10·0 mL fcK;r:R ~'P1T I 7ffi:: 25° C 1R ~ fcK;r:R CflT Yo(.l<:-lo(.u~ ~ 13·3 mm Hg m, "ffi mif.:r CflT

l1Tffi $\ CX-l111 rj Cf<IT ~ ?

(R = 0·0821 L atm mol-1 K-1 31R 760 mm Hg = 1 atm.)3l?rcrr

(a) HkjrC:1r~dit Cf<IT ~ ~ :

(i) 3-lUJ~~ "TT~(ii) fcK;r:R cn1 .i1

(b) ~ ~ ~ 1R ~ ~ ~ f1rc;mr if ~ rjl~~I\!jrj CflT ~ Cf<IT ~ ? ~

~ fcfi Cf11l 25° C ~ 31R ~ ~ ~ 1QCl1lr~~o(. t 31R ~ if ..~,) ..CflT l1Wr am 0·78 ~ I [rjl~~I\!jrj ~ ft;rQ: KH = 8·42 x 10-'-:7M/mm Hg]

29. (a) Write chemical equations to illustrate the following name bearingreactions:(i) Cannizzaro's reaction(ii) Hell-Volhard -Zelinsky reaction

(b) Give chemical tests to distinguish between the following pairs ofcompounds:(i) Prop anal and Propanone(ii) Acetophenone and Benzophenone(iii) Phenol and Benzoic acid 5

OR

(a) How will you bring about the following conversions :(i) Ethanol to 3-hydroxybutanal(ii) Benzaldehyde to Benzophenone

(b) An organic compound A has the molecular formula CSH1602' Itgets hydrolysed with dilute sulphuric acid and gives a carboxylicacid B and an alcohol C. Oxidation of C with chromic acid also

produced B. C on dehydration reaction gives but-l-ene. Write

equations for the reactions involved. 5

56/3 10

(a) rrjkjrc1~d ~ ~3TI cit '('1<:iI~HCP W-llcp'('UI W ~ ~ :(i) ~H~I~ ctt ~

(ii) ~-~-~rC1«h1 ~

(b) rrjkjrc1r~d ~ ~ # f~ cn1 ~ ~ ~ ft;m: ~-~ '('1<:iI~Hcp ~

~:

(i) ~ 31R >WAR #

(ii) Q<:ilcllhlrjlrj ~ ~o;J1llhlrjlrj #(iii) ~ ~ ~~sCP ~ #

3l~

(a) rrjkjrc1r~d ~yid'('UI ~ ~ ~ :

(i) ~ cit 3-QI$~Tq+fl~~rjc1 #(ii) ~~rc:-s()ls-s cit ~o;J11lhl·.flrj #

(b) ~ ~ men A (31TfUq-q:; ~ CSH1602) cit C11 <:iC'.~Cp ~ -B

~-3-il.j~r2.d ~ 1l'<1T ~ ~ CPlafITCK1rC1CP~ B ~ ~ Qc:cnIQlc1 C

r ~:m I C ~ ~ ~ ~ ~ dY-q~rj -B 'lft B >rT({f mcrr ~ I

C CfiT H~c1lcp'('ul ~ 'R ~-l-B >rT({f mm ~ I <:ir?\fQd 3WmT3TI ~ fc;m:

" ?""~<:il-\lcp'('UI CfiT I\'II~~ I

30. (a) Draw the structures of the following :

(i) XeF4

(ii) H2S207

(b) Explain the following observations:

(i) Phosphorus has a greater tendency for catenation thannitrogen.

(ii) The negative value of electron gain enthalpy is less forfluorine than that for chlorine.

(iii) Hydrogen fluoride has a much higher boiling point thanhydrogen chloride. 5

OR

~~ I1-

56/3 11 . P.T.D.

~~-~1~--------~~-~------~---------------------J1

(a) Draw the structures of the following :

(i)

(ii)

PCIs (s)

802-3

(b) Explain the following observations:

(i) Ammonia has a higher boiling point than phosphine.

(ii) Helium does not form any chemical compound.

(iii) Bi (V) is a stronger oxidising agent than 8b (V).

(a) H~r\1r~~ cfiT ~,,:qrll~ ~ ~ :

(i) XeF4

(ii) H28207

(b) H~r~r~~ 3-fC/ctlChrllc€r cx:m§'1T ~ :

(i) rll~~I'Jjrl c€r ~ ~I~~I"'~ if ~ c€r ~ 31f'i::fCfi·Wffi ~ I

(ii) ~~~Irl ~ ~ cor ;t~.uII("+iCh~. 'Rj~ ~. ~ ~ ~~cp11mm~ I

(iii) QI~~I'Jjrl cK1l"'I~S c€r ~ Qj~~I'Jjrl 1:Rj~ cor q:q~ ~ 31f'i::fCfi

mm ~ I

31~

(a) H~r\1r~~ c€r ~",-qrll~ ~ ~ :

(i) PCIs (s)

(ii) 80;-

(b) H~r\1r~~ 3-fC/\1IChrll~ 31f'iW: ~ ~ :

(i) ~1~lrl c€r ~ ~ cor q:q~ ~ mm ~ I

(ii) Qlr~~+i ~ "'1~I~HCh~ ~ ~ ~ I

(iii) 8b (V) c€r ~ Bi (V) ~ 31f'i::fCfi >I'if0 ~Y-qI~Ch ~ I

5

56/3 12 97,100