'Series 50S I Code N~. 56/1

Q5)s ~ . :iIii1

Roll No. I I II I I I I Candidates must writ,e the Code on~ ;f I I I I I I I I the title page of the answer-book.

. ~ afTW m Q)) 3't'R -~"q)T -a, 1j'X9 - ~

tR~~1

i i. Please check that this question paper contains 12 printed pages. ! ';)",'

. Code number given on the right hand side of the question paper should be twritten 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. to

10.30 a.m., the students will read the question paper only and will notwrite any answer on the answer script during this period.

. ~ ~ ~ ~ fCfi ~ m-~ # ~ ~ 12 ~ I

. m-~ # ~ ~ ~ ~ ~ ~ ~ ~ qj) ~ ~-~~ ~ 1J&-~ -q'{ ~ I

. ~ ~ "Cfi"'{ ~ fCfi ~ m-~ # 30 m ~ I

. ~m~~~~~~~,~~~~~1

. ~ m-~ qj) ~ ~ ~ 15 fir;R: "qjT ~ fGt1T ~ t 1 m-~ "qjT fq'(f{ur ~ #

10.15 ~ f4;7o1r ~ I 10.15 ~ ~ 10.30 ~ '('f'q=j ~ ~ m-~ qj) ~ ~

~ ~ ~ ~ ~ ~-~~ -q'{ ~ ~ ~ ~ I

CHEMISTRY (Theory)

~'t1lq~ fa~R (~c.9.I~<t»

Time allowed: 3 hours Maximum Marks: 70

R~ ~ : 3 FITTi?:: 31ti:1q;rrJ1 3i?!fi : 70

56/1 1 P. T .0.

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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 and

carry 1 mark 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.

H/~/-<I ~ :

(i) "fit m 31Rqr2f ; I

(ii) ~ m iJ; ~ 3fq; G'"\9Jk "1Tl:?" ~. I

(iii) m-m, 1 'fl8 nq;- 3:rfrr '(';ffj-:'3"ffftlT m ~. I ~ m iJ; ft1Tl: 1 3fq; ~ I

(iv) m-m, 9 'fl18 nq;- '(';ffj-:'3"ffftlT m ; I ~ m iJ; ft1Tl: 2 3fq; ~. I

(v) m-m, 19 'fl27 nq;- 7ft '(';ffj-:'3"ffftlT m ~. I ~ m iJ; ft1Tl: 3 3fq; ~. I

(vi) m-m, 28 'fl30 'cftFj-:'3"ffftlT m ~. I ~ m iJ; ft1Tl: 5 3fq; ; I

( vii) 31/ q' ii i.j q, <1/ j t1' / < Mf7T ~ q;r m qjf I #i"<'ji"N2"U" iJ;;:JTrljt1J qft 3fj11fff ~ .~ I

1. Define 'order of a reaction'.

.'3i~~ q;1~' 'qj) ~ ~ I2. What is meant by 'shape selective catalysis' ?

, ~ 3Tr'i:"frf{ff ( ~ -~~ fCfC:q ) ~' CiiT ~ 31'4 mm ~ ?

3. Differentiate between a mineral and an ore.

~~~~~-q:3tw~~ I

56/1 2

--cc,~

'I

4. What is meant by 'lanthanoid contraction' ? 1

'~~-110!4-5 ~' ~ ~ ~ ~ ?

5. Write the IUP AC name of the following compound: 1

CH2 = CHCH2Br

11k11(.1~d ~ "q)"T 31r;f;.~'q1.1;.m. (IUPAC) ~ ~ :

CH2 = CHCH2Br

6. Draw the structure of 4-chloropentan-2-one. 1

4-q.<:"J1\1~;?:-1-2-:ift;r ~ ~ 3:r~ ~ I

7. How would you convert ethanol to ethene ? 1

~ ~ ~ # a:rrq i1:r ~yidRd ~ ?

8. Rearrange the following in an increasing order of their basic

strengths: 1

C6H5NH2, C6H5N(CH3)2' (C6H5)2NH and CH3NH2'Rk1I(.1~d ~ ~ ~ ~ ~ ~ ~ # ~ ~ ~ :

C6H5NH2' C6H5N(CH3)2' (C6H5)2NH ~ CH3NH2'

9. Explain how you can' determine the atomic mass of an unknown metal

if you know its mass density and the dimensions of unit cell of its

crystal. 2* 31N ~ ~ ~ "q)"T ~CX.j~I-i ~ ~ ~ ~ ~ ~ ~ ~~-~ (~) ~ m m ~ ~ ~CX.j~I-1 i1:r ~ ~? CX.j1~1

~I

10. Calculate the packing efficiency of a metal crystal for a simple cubiclattice. 2

~ ~-1lcfJl( ~ (~ ~ ~) ~ fu{{ ~ ~ ~ ~ ~ ~

yRcfJl(.1d ~ I

11.' State the following: 2

(i) Raoult's law in its general form in reference to solutions.

(ii) Henry's law about partial pressure of a gas in a mixture.

Rk1I(.1I~d "q)"T "qj~ ~ :

(i) ~{10!4-1'i ~ ~ # ~I~I~ ~ # ~ "q)"T ~ I

(ii) f4~ # ~ ~ ~ ~ ~ ~ ~ # ~ "q)"T ~ I

56/1 3 P.T.D.

- -

III_IIIII= --

12. What do you understand by the rate law and rate constant of a

reaction? Identify the order of a reaction if the units of its rate

constant are : ~

Ci) L -1 mol s-1

Cii) L mol-,-1 s-1

31fq~3l~~~~~~~~~~~ ?~~~

1r1~I(.1I~(1 ~ ~ 3:{fi:{~ ~ W ~ ~ ~ :

Ci) L -1 mol s-1

c o. ) L 1-1-1 11 mo s

13. The thermal decomposition of HCO2H is a first order reaction with a

rate constant of 2.4 x 10-3 s-1 at a certain temperature. Calculate how

c, long will it take for three-fourths of initial quantity of HCO2H to

decompose. Clog 0.25 = - 0.6021)

~ ~ "ffit1" -q"{ 2.4 x 10-3 s-1 ~ ~ ~ ~ ~ HCO2H "qjT ~ ~ ~

~ W ~ 3l~ mm ~ I I.IR~(.1~ ~ HCO2H ~ ~ ~ ~ "CfiT

~ ~-~~ ~ ~ ~ ~ ~ ~ I (log 0.25 = - 0.6021)

14. Describe the principle controlling each of the following processes:

Ci) Vapour phase refining of titanium metal

Cii) Froth floatation method of concentration of a sulphide ore

1r1~I(.1I~(1 ~ ~ ~ R~ ~"qjT quf;:r ~:

Ci) G1~~'Jr ~ ~ qf&1 ~ I.IR~(UI

Cii) ~~I~.s ~ ~ ~ ~ m ~ ~

56/1 4

\

15. How would you account for the following: . 2

(i) Cr2+ is reducing in nature while with the same d-orbital

configuration (d4) Mn3+ is an oxidising agent.(ii) In a transition series of metals, the metal which exhibits the

greatest num.ber of oxidation states occurs in the middle of the

serIes.~I~~ ~ "q)RUT ~ ~ ~ :(i) Cr2+ ~ 31'rT.\I~-q; ~ ~ ~ d-31Tffi~ ~ (d4) $ ~ Mn3+ ~

-a:q T.\ 11.fq;j m-cn ~ I(ii) ~ ~31T ~ M 9)uft #, -m ~ d~ ~ # ~:q~~ ~~ ~

~ -qR"rT ~, ~ 9)uft $ ~ # ~ ~ ~ I

16. Complete the following chemical equations: 2

- 2-(i) MnO 4 (aq) + 82°3 (aq) + H2O (l) -t

)i (ii) Cr20~- (aq) + Fe2+ (aq) + H+ (aq) -t

OR

,~ 8tate reasons for the following: 2

(i) Cu (I) ion is not stable in an aqueous solution.

(ii) Unlike Cr3+, Mn2+, Fe3+ and the subsequent other M2+ ions of

the 3d series of elements, the 4d and the 5d series metals

generally do not form stable cationic species.

~I~~ ~m ~Cf>~ ~. 1iUT ~ :

. - 2-\ (1) Mn? 4 (aq) + 82°3 (aq) + H2O (l) -t

\ (ii) Cr20~- (aq) + Fe2+ {aq) + H+ (aq) -t

,:

31~

~I~~ $ "q)RUT ~ :(i) Cu (I) ~ ~ ~ # ~ ~ m-cn ~ I

(ii) ~ ~ 3d 9)uft # Cr3+, Mn2+, Fe3+ ~ ~ # M2+ ~ $ ~ 4d

~ 5d~$ ~~I~I~a:~~ ~~~~~ I

56/1 5 P.T.D.

...

---"'1 8-. ~i~~"

...

-'..,...

, ~f';~ '

17. Explain what is meant by the following: 2

(i) peptide linkage

(ii) pyranose structure of glucose

-m ~ ~ R~I~I~d ~ ~ ~ ~ ~ :

(i) ~~ ~

(ii) l~~ ~ fq~ ~

18. Write the main structural difference between DNA and RNA. Of the

four bases, name those which are common to both DNA and RNA. 2

DNA ~ RNA.q ~ ~~-q-1I~<;t} 3:tw ~ ~ I "'qR ~ .q ~ ~ ~

~~~~.q'Qr(!:~~ I

19. A solution prepared by dissolving 8.95 mg of a gene fragment in

35.0 mL of water has an osmotic pressure of 0.335 torr at 25° C.

Assuming that the gene fragment is a non-electrolyte, calculate its

molar mass.

~ ~ 35.0 mL .q ~ ~ ~ ~ ~ 8.95 mg ~ ~ ~ ~ lfqT

~ 25° C ~ ~(I~(Un ~ 0.335 torr ~ I ~ ~ ~ fCfi ~ ~

~37{~ ~, ~ 31fUTq (~) ~~~I-1 ~ ~ I20. Classify colloids where the dispersion medium is water. State their

characteristics and write an example of each of these classes.

OR

Explain what is observed when

(i) an electric current is passed through a sol(ii) a beam of light is passed through a sol

(iii) an electrolyte (say NaCl) is added to ferric hydroxide sol

'q~ ~ ~ ~ "i:t>1~ ~ CfI1T<;t}(UI ~ I ~ qrf ~ ~mm ~

~-~ ~<:.I~(UI ~ I

3t~

~I~I ~ fCfi ~ mm ~ ~

(i) M ~.q ~ ~V:m:r ~ ~~ ~

(ii) ~~~m~~M~.q~~~~~

(iii) ~ ~~ (~ NaCl) W ~1~~I~I~.s ~ .q :sTffi ~ ~

56/1 6

Ei\ii;

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c...'~;~",;~,:1. How would YOU account for the following: 3 ~W ,,\

(i) H2S is more acidic than H2O. "i

(ii) The N - 0 bond in NO; is shorter than the N - 0 bond in NO;.

(iii) Both 02 and F 2 stabilize high oxidation states but the ability of

oxygen to stabilize the higher oxidation state exceeds that of

fluorine.~~fctft9""(1: ~ ~ ~ ~ :

(i) H2O ~ ~ H2S 31f'/;:{qi ~ ~ I

(ii) NO; ~ N-O ~ NO; ~ N-O ~"iI; ~ mm ~ I

(iii) 02 ~ F 2 ~ m ~ ~ 31"CfT!lJ.T311 ~ ~~ ~ ~ ~ ~

~~~~~~~~I

22. Explain the following terms giving a suitable example in each case: 3

(i) Ambident ligand

(ii) Denticity of a ligand(iii) Crystal field splitting in an octahedral field

~~~~f;{~~~~~~~:

(i) "3cq~ ~ (Ambident ligand)

(ii) ~ ~ ~ (Denticity)

(iill 31~'t:fi~ ~ ~ ~ ~ ~23. Rearrange the compounds of each of the following sets in order ofreactivity towards SN2 displacement: 3

(i) 2-Bromo-2-methylbutane, l-Bromopentane, 2-Bromopentane

(ii) l-Bromo-3-methYlbutane,2-Bromo-2-methYlbutane,

3-Bromo-2-methylbutane

(iii) l-Bromobutane, l-Bromo-2,2-dimethylpropane~\ l-Bromo-2-methylbu~ane .

t; ~~~~~~~~SN2~~~~~~~:;. (i) 2-~-2-il~~~~' 1-~~~' 2-~~~

(ii) 1-~-3-il~~~~' 2-~-2-~~~~' 3-~-2-~~~~

(iii) l-~m~~, 1-~-2,2-~~~' 1-~-2-ilf~~~~

56/1 7 p.T.G.

- ~

.

24. How would you obtain the following: 3

(i) Benzoquinone from phenol

(ii) 2-Methylpropan-2-o1 from methylmagnesium bromide

(iii) Propan-2-o1 from propene

31fq" R~I~I{gd ~ ~ ~ :

(i) ~ ~ ~~II~-1I-1

(ii) itr~~~J-1I~I~"i ~~ ~ 2-itf?:r~-2-~

(iii) ~ ~ ~-2-~

25. State reasons for the following: 3

(i) pKb value for aniline is more than that for methylamine.

(ii) Ethylamine is soluble in water whereas aniline is not soluble in j

I

water. . ,

I

I

(iii) Primary amines have higher boiling points than tertiary amines. ~

1-1~I~I{gd ~ q:jT\UT ~ :

(i) -Q:R'ffio;r ~ ~ pKb 'qjT ~ 31~ itr~~ ~ 31f"i:"fq; ~ ~ I

(ii) ~~~~"iI-1 ~ if ~~ ~ ~ "Q:~ ~ if ";f/J ~ I(iii) )jl~fq~ ~ ~ -q:q~-1i~ ~ ~ ~ 3Tfi.:rCfI ~ ~ I

26. Draw the structures of the monomers of the following polymers: 3

(i) Polythene

(ii) PVC j

(iii) Teflon 11

R~I~I{gd ~~~ ~ ~~"CfIT ~~ ~ : I(i) ~\!ft';:r

(ii) PVC

(iii) ~

56/1 8

of f

I

--~-- ~

---

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

" (i) Food preservatives

(ii) Synthetic detergents(iii) Antacids

1"i~I~I~d ~ ~ ~ ~ ? ~ "SI"q:jR "q)T ~-~ ..1~I~(UI ~ I

(i) "&ro ~

(ii) ~~~~d 31-q~

(iii) -Q:;c:Tfu:s (Antacids)

28. (a) What type of a battery is lead storage battery? Write the anodeand cathode reactions and the overall cell reaction occurring inthe operation of a lead storage battery.

(b) Calculate the potential for half-cell containing0.10 M ~Cr207 (aq), 0.20 M Cr3+ (aq) and 1.0 x 10-4 M H+ (aq)

The half-cell reaction is

Cr20~- (aq) + 14 H+ (aq) + 6 e- ~ 2 Cr3+ (a~) + 7 H2O (l),

and the standard electrode potential is given as Eo = 1.33 V. 5

OR

(a) How many moles of mercury will be produced by electrolysing

1.0 M Hg(NO3)2 solution with a current of 2.00 A for 3 hours?

[Hg(NO3)2 = 200.6 g mol-I]

(b) A voltaic cell is set up at 25° C with the following half-cells ~,

Al3+(0'001 M) and Ni2+(0.50 M). Write an equation for the ~~.,:,

reaction that occurs when the cell generates an electric current.. : f_:

and determine the cell potential. '::::~~,t "0 0 ~

(Given: E

2+/ = - 0.25 V, E 3+/ = ,-- 1.66 V) r~.;!;N .

N . AI AI . '. .1 1 5 f'~'. ., ~\;:

(a) ~ ~ ~ I (.j ctI ~ ~ "SI"q:jR ~. ~ ~ ? ~ ~-:qT11"q;)" ~ ~ "q:jT1=f ~ -q'{ ~';: ij~,'

~ ~ ~ t~ -q'{ 31~~ ~ ~ ~ ~-fif~ ~ ~ 31~ ~ :~;~r;':~ ~ i~Fi_,. I :_~~ft:c

Q, I\,I~~ . :;;;e:'

(b) 0.10 M ~Cr207 (aq), 0.20 M Cr3+ (aq) ~ 1.0 x 10-4 M H+ (aq) ':i,

., 4. "'-~.;: ~~ ..~_. F;;,~ ~ .;rql~ ~~-~~ "q)T Ig~g '11\q)I~(l 'f)11"l~ I ~;, "~

31tf-~ ~~ ~ "SI"q:jR ~ ~ ~ '."

Cr20~- (aq) + 14 H+ (aq) + 6 e- ~ 2 Cr3+ (aq) + 7 H2O (l),

~ ~ "J:rR'"q:j ~~s fcfi:rq ~ ~ ~, Eo = 1.33 V.

3:r~

56/1 9 P.T.D.

~ ~

.-~J~I. !

\

.Ii -, (a) 3 ~ ~ 'f(;nr; 2.00 A ~ ~ ~ ~ ~ * 1.0 M Hg(N03)2'~

"~ 'q:jT ~ - 31f:ff1G;;r ~ '\jffifT ~ m ~ ~ ~ W 'q:jT d ~ I c:: wi W1T ?

; [Hg(N03)2 = 200.6 g mol-!]

(b) ~ 'q1~ ~ q;1 25° C ~ ~ 3fff-~ ~ ~ ~ ~ '\jffifT ~ :

Al3+(0.001 M) ~ Ni2+(O.50 M). ~ 3=1~ 'q:jT ~1.i1~{UI ~ "\jf) ~

~~~~~~mm~~~'q:jT~~~ I

(~ ~ ~ : E~i2+/Ni = - 0.25 V, E~3+/Al = - 1.66 V)

29. (a) Draw the structures of the following molecules:

(i) (HP03'3

(ii) BrF3

(b) Complete the following chemical equations:

(i) HgCl2 + PH3 ~

(ii) S03 + H2SO4 4

(iii) XeF 4 + H2O ~ 5

OR

(a) What happens when

(i) chlorine gas is passed through a hot concentrated solutionof NaOH ?

(ii) sulphur dioxide gas is passed through an aqueous solutionof a Fe (III) salt?

(b) Answer the following:

(i) What is the basicity of H3P03 and why?

(ii) Why does fluori:ne not play the role of a central atom in

interhalogen compounds?

(iii) Why do noble gases have very low boiling points? 5!

56/1 10

--'- ..

-~ .~IIIIIIII

~ ,",",", c",- ~.

(a) R~I~I(gd 3:j1J]ift i:fi1 ~~ 31RfuJ"(f ~ :

(i) (HP03)3

(ii) BrFs

(b) Irj~I~I(gd ~1~1~lrjctl ~l1lct1~Un ~ 1[{T ~ :

(i) HgCl2 + PH3 ~

(ii) S03 + H2SO4 ~

(iii) XeF 4 + H2O ~

a:r~

(a) 'q:<:rT ~ ~ ~( i ) N a o H ~ ~ 1T{!:I" ~ # "CR'!l-U-;:r ~ ~ i:fi1 \3fT"ffi ~ ?(ii) Fe (III) ~ ~ ~ ~ # ~ ~ ~~~ ~ ~ i:fi1

\3fT"ffi~?

(b) R~I~I(gd ~ ~ ~ :

(i) H3P03 i:fi1 ~ (basicity) 'q:<:rT ~ ~ ~ ?

(ii) ~~~I~~I'.31rj ~ # ~ifrf:rri, ~ -q"{J:JTUJ i:fi1 ~ ~ ~ ~ mm~ ?

(iii) ~ (~) ~ ~ ~~rjictl ~ ~ ~ ~ ~ ,?',.c~,;;

30. (a) Illustrate the following name reactions:

(i) Cannizzaro's reaction

(ii) Clemmensen reduction

(b) How would you obtain the following: "

(i) But-2-enal from ethanal

(ii) Butanoic acid. from butanol

(iii) Benzoic acid from ethylbenzene 5

OR

(a) Give chemical tests to distinguish between the following:

(i) Benzoic acid and ethyl benzoate

(ii) Benzaldehyde and acetophenone

56/1 11 P.T.D.

""':-

(b) Complete each synthesis by giving missing reagents or productsin the following:

(( COOH SOCl2(i) I ~

~ COOH heat

H2NCONHNH2

(ii) C6H5CHO ~

(iii) 0= CH2 ~ 0- CHO 5(a) l-1k"fl~l(gd ';fT1=f 'CiRYit ~31T ~ d~I~(UI ~ :

(i) tmro ~ ~

(ii) ~1~~-1 ~~-q~-1

(b) R k"f I ~ R9 d -qj) a:rrq ~ '5rTl:{f ~ :

(i) ~ ~ ~-2-~

(ii) ~~ ~ ~~~ ~

(iii) ~1~~~~I-1 ~ ~~ ~

3t~

(a) Rk"fl~R9d # ~ CfiG ~ ~ (1~I~RctI -q~ -qj) ~ :

(i) ~~~~~~~

(ii) ~~I('".s~I~.s ~ ~~IGI~I-1I-1

(b) Rk"fl~l(gd -ij ~~ 31~ ~ ';jJf -;r ~ ~ ~ ~ I~(gctl( ~

~~ -qj) 1uf ~ :

(( COOH SOCl2(i) I ~

~ COOH ~

H NCONHNH

(ii) C6H5CHO 2 2 ~

(iii) 0= CH2 ~ 0- CHO

~~i ~~,~;qj~r.;l:\;;;";56/1 12 - '-,:"J.,