11 chemistry solved 05 new sol sdg

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SAMPLE PAPER-05 (solved)

CHEMISTRY (Theory)

Class – XI

Time allowed: 3 hours Answer Maximum Marks: 70

1. Total number of electrons in f subshell is 14 but half of them will have the same spin i.e. 7

electrons will have same spin.

2. We have q = – w = pex (10 – 2) = 0() = 0

!o wor" is #one$ no heat is absorbe#.

%. &e'2 is a linear molecule with '&e' bon# anle as 10*. +lthouh the &e' bon#s are

polar, the bon# polarities cancel each other an# the net #ipole moment is -ero.

4.

i) / '2 (steam) / '2

ii) / '2 (steam) / '2 2 / 2'2

. , +l, 3n, e, u.

5. The metals of roups 7, an# 6 #o not form h#ri#es. This reion of perio#ic table from

roup 7 to 6 is referre# to as h#ri#e ap. 'eav water is use# in the nuclear reactors to slow

#own the spee# of neutrons (as mo#erator).

7. arbon #io8i#e absorbs 9: ra#iations from atmosphere which lea# to lobal warmin. ;o, if

carbon #io8i#e level increases beon# 0.0%<, the natural reenhouse balance ma et

#isturbe#. ;o it is consi#ere# as serious pollutant.

. +s we o awa from the nucleus, the effective nuclear chare pull oes on increasin. 'ence

electrons present in 4p orbital e8perience the lowest effective nuclear chare.

6.

a) 3 2 3 3 2 3 3CH CH CH(CH ) C(CH ) CH(CH ) CH CH− − − − − −

b) 3 3 2 2 3 3CH CH(CH ) CH CH CH(CH ) CH− − − − −

r

a)





b)

10.

a) Wavelenth #ecreases with increase in velocit of movin particle.

b) +nular momentum of %p an# 4p orbitals will be same because l = 1 for porbital.

11.

a) 9nitiall the vapour pressure will #ecrease.

b) The rate of evaporation remains constant at constant temperature in a close# vessel.

&ut the rate of con#ensation will be low initiall because there are fewer molecules per

unit volume in the vapour phase an# hence the no. of collisions per unit time with the

li>ui# surface #ecreases.

12.

a) &arium an# &erllium sulphate can be #istinuishe# b solubilit test. &erllium

sulphate is soluble in water an# barium sulphate is insoluble in water.

b) &arium carbonate is thermall most stable al"aline earth metal carbonate because$ its

ion bein larer in si-e is more stabili-e# b larer carbonate ion throuh the

formation of stable lattice.

1%.

a) The wor# ?he8ane@ in#icates the presence of 5 carbon atoms in the chain. The

functional roup chloro is present at carbon 2. 'ence, the structure of the compoun#

is '%'2'2'2' (l)'%.

b) The wor# ?pent@ in#icates that parent h#rocarbon contains carbon atoms in the

chain. ?en@ an# ?ol@ correspon# to the functional roups = an# ' at carbon atoms 4

an# 2 respectivel. Thus, the structure is '2=''2' (') '%.

c) ;i8 membere# rins containin a carboncarbon #ouble bon# is implie# b

cclohe8ene, which is numbere# as shown in (9). The prefi8 %nitro means that a nitro

roup is present on %. Thus, complete structural formula of the compoun# is (99).

Aouble bon# is suffi8e# functional roup whereas !2 is prefi8e# functional roup

therefore #ouble bon# ets preference over –!2 roup





#) ?1ol@ means that a ' roup is present at 1. ' is suffi8e# functional roup an#

ets preference over = bon#. Thus the structure is as shown in (99)

r

!'% has a hiher #ipole moment than !%. 9n case of !'% orbital #ipole #ue to lone pair is in

same #irection as resultant #ipole #ue to three !' bon#s. Therefore lone pair moment a##s

on the resultant #ipole of !' bon#s. 9n case of !% orbital #ipole #ue to lone pair is in

opposite #irection as resultant #ipole #ue to three ! bon#s. Therefore lone pair moment

cancels the resultant #ipole of ! bon#s.

14. The entrop of all substances at absolute -ero (0 B) is ta"en as -ero because of complete

or#er in the sstem. That is the atoms or molecule #o not move at all in the perfectl

crstalline state.

0 2.303 logG RT K ∆ = −

= 2.%0% 8 .%14 C B1 mol1 8 26 B lo 5.5 8 10

= 16.147 C 8 26 lo 5.5 8 10

= 70. Dlo 5.5 / lo 10E

= 70. D0.16 / .0000E

= 70. 8 .16 C = %%204.60% C

0 133.205G kJmol −∆ = −





1.

a) ritical temperature – 9t is the temperature above which a as cannot be li>uefie#.

b) +voa#ro law – F>ual volumes of all ases contain e>ual number of molecules at same

con#itions of temperature an# pressure.

c) harles Gaw – Hressure remainin constant, the volume of a fi8e# mass of a as is

#irectl proportional to its absolute temperature.

15.

a) ;o#ium h#ro8i#e an# h#roen as will be forme# which will catch fire

2 22 ( ) 2 ( ) 2 ( ) ( ) Na s H O l NaOH aq H g+ → +

b)

;o#ium pero8i#e is forme#2 2 22 Na O Na O+ →

c) ;o#ium h#ro8i#e an# h#roen pero8i#e are forme#

2 2 2 2 22 2 Na O H O NaOH H O+ → +

17. 2 is best o8i#i-in aent because it has hihest stan#ar# re#uction potential. 9t has low bon#

#issociation ener, hih electron affinit an# hihest h#ration ener of ions.

'9 is best re#uctnt #ue to low bon# #issociation ener.

1.

i) 3 2 62 6 6 BF LiH B H LiF + → +

ii) 2 6 2 3 26 2 ( ) 6 B H H O B OH H + → +

iii) 2 6 42 2 NaH B H NaBH + →

iv) 3 3 3 2 H BO HBO H O∆

→ +

v) 33 ( ) 3 Al NaOH Al OH Na+ → +

vi)

2 6 3 3 3 6 23 6 2 12 Heat B H NH B N H H + → +

16. Haper chromatoraph – it is a tpe of partition chromatoraph. + special >ualit of paper

"nown as chromatoraphic paper is use# which traps water an# act as a stationar phase.

The mi8ture of components is #issolve# in suitable solvent. This solvent act as a mobile

phase. 9t is base# on continuous #ifferential partitionin of components of mi8ture between

stationar an# mobile phase.

20.





i) +ci# rain – 9t is a rain which contains water alon with sulphuric aci#, nitric aci# an#

h#rochloric aci# which are forme# from the o8i#es of sulphur, nitroen an# 2

present in the air as pollutants an# has a p' of 4.

ii) Futrophication – 9t refers to the aein of the confine# water bo#ies, for e8ample

la"es. !ormall it is a slow eoloical phenomenon but the process is accelerate# #ue

to the flow of e8cessive nutrients into the la"e. F8cessive flow of fertili-ers, pestici#es

etc., into the la"e lea# to the alae bloom that ultimatel lea#s to the #eath of a>uatic

life. The #ea# matter sin"s to the bottom of the la"e ma"in la"e shallow an# marsh.

iii) Ireen hemistr – The term reen chemistr is use# to refer the proce#ures of

snthesis of chemical of our nee#s throuh a process that neither use nor emit to8ic

chemicals. or e8ample earlier chlorine as was use# for bleachin paper which is a

hihl to8ic as but it has now been replace# b h#roen pero8i#e with a suitable

catalst.

21.

i)

rbit rbital

1 rbit is a well#efine# 2A

circular path aroun# the

nucleus in which the

electrons revolve.

rbital is a %A space aroun# the

nucleus within which the

probabilit of fin#in the

electrons is ma8imum.

2 oncept of rbit is not in

accor#ance with the wave

nature of electrons

9t is in accor#ance with the

wave nature of electrons

% rbits #o not have

#irectional characteristics

+ll orbitals e8cept sorbitals

have #irectional characteristics

ii) Jncertaint in spee#0.005

600100

V x∆ = mKs = 0.0% m s1

'eisenber Jncertaint Hrinciple

x4

h x m V

π

∆ ∆ =





34

31 1

6.626 x10 =

224 x x 9.11 x 10 x 0.03

7

Js x

kg ms

−

− −

∆ = 1.6% 8 10%m

22.

i) +nions are forme# when a neutral atom ains one or more electrons. ;ince the

number of electrons increases an# the number of protons remains same, the effective

nuclear chare #ecreases which results in #ecreases in ionic ra#ii.

ii) Aue to the halffille# orbital nitroen 1s2 2s2 2p%, the stabilit of this confiuration is

more an# ioni-ation ener is hiher than o8en.

iii) Aue to the smaller si-e an# seven electrons in its outermost shell, incomin electrons

e8perience less attraction in . hence less ener will be release# in case of than l.

2%.

a) 0.1 nm

b) 9t is #one to screen an un#esirable or #anerous items carrie# b passeners.

c) Gife imprisonment for such crimes can be useful to prevent smulin

24.

a)

;pecies onLuate +ci# onLuate &ase

'2 '%/ OH −

3HCO−

'2%3

CO−

4HSO − '2;4 2

4SO −

!'% 4

NH+ 2

NH−

b)

or the reaction 4 2 2CH (g) + H O (g) CO (g) + 3H (g)⇌

i) 2

4 2

3

CO H

p

CH H O

(p ) (p )K =

(p ) (p )

ii)

a) n increasin pressure, the reaction e>uilibrium will shift in the bac"war# #irection.

b) There is no effect of catalst in e>uilibrium composition$ however the e>uilibrium will

be attaine# faster.

r





a) !a! , !a!2 – ;olution are basic as the are salts of stron base an# wea" aci#. ('!

an# '!2 are wea" aci#s an# !a' is stron base). !'4!% 9ts solution is aci#ic as it

is salt of stron aci# ('!%) an# wea" base (!'4').

b) B&r This solution is neutral as it salt of stron aci# '&r an# stron base B'.

2. 3 2 2 2 2 3CH - CH - CH - CH - CH - CH nhe8ane

3 3 2 2 3CH - CH (CH )- CH - CH - CH 2ethlpentane

3 2 3 2 3CH - CH - CH (CH )- CH - CH %ethlpentane

3 3 2 2 3CH - C (CH ) - CH - CH 2,2Aimethlpentane

3 3 3 3CH - CH(CH ) - CH(CH ) - CH 2,%Aimethlbutane

r

a) Wac"er@s metho#.

i. Fcofrien#l an# safest metho#.

ii. 9t ives 60< iel#.

b) 9n Wac"er@s metho#,

2 2 2PdCl / ai r / Cu Cl

2 3R - CH = CH R - CO - CH →

2 2 2PdCl / ai r / Cu Cl

2 2 3CH = CH CH CHO → −

c) ';4 is unsafe for the environment.

25. ;tep 1 The s"eletal ionic e>uation is

2- 2- 3+ 2-

2 7 3 4Cr O (aq)+SO (aq) Cr (aq)+SO (aq)→

;tep 2 +ssin o8i#ation numbers for r an# ;

+6 -2 +4 -2 +3 +6 -2

2 7 3 4Cr O (aq)+ S O (aq) Cr (aq)+ S O (aq)→

;tep % alculate the increase an# #ecrease of o8i#ation number, an# ma"e them

e>ual

+6 -2 +4 -2 +3 +6 -2

2 7 3 4Cr O (aq)+ 3S O (aq) 2Cr (aq)+ 3S O (aq)→

;tep 4 +s the reaction occurs in the aci#ic me#ium, an# further the ionic chares are not

e>ual on both the si#es, a## '/ on the left to ma"e ionic chares e>ual

2- 2- + 3+ 2-

2 7 3 4Cr O (aq)+3SO (aq)+8H 2Cr (aq)+3SO (aq)→

;tep inall, count the h#roen atoms, an# a## appropriate number of water molecules

on the riht to achieve balance# re#o8 chane.

2- 2- + 3+ 2-

2 7 3 4 2Cr O (aq)+3SO (aq)+8H (aq) 2Cr (aq)+3SO (aq)+4H O→





r

Hb%4 is actuall a stoichiometric mi8ture of 2 mol of Hb an# 1 mol of Hb 2. 9n Hb2, lea# is

present in /4 o8i#ation state, whereas the stable o8i#ation state of lea# in Hb is /2. Hb 2

thus can act as an o8i#ant (o8i#isin aent) an#, therefore, can o8i#ise l– ion of 'l into

chlorine. ;ince Hb is a basic o8i#e, the reaction

Hb%4 / 'l %Hbl2 / l2 / 4'2 can be splitte# into two reactions namel

2Hb / 4'l 2 Hbl2 / 2'2 (aci#base reaction)

/4 –1 /2 0

Hb2 / 4'l Hbl2 / l2 /2'2 (re#o8 reaction)

;ince '!% itself is an o8i#isin aent therefore, it is unli"el that the reaction ma occur

between Hb2an# '!%. 'owever, the aci#base reaction occurs between Hb an# '!% as

2Hb / 4'!% 2Hb(!%)2 / 2'2

9t is the passive nature of Hb2 aainst '!% that ma"es the reaction #ifferent from the one

that follows with 'l.

11 chemistry solved 05 new sol sdg

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