KENDRIYA VIDYALAYA

SANGATHAN, AGRA REGION

SESSION ENDING
CLASS: XI EXAM (2023-24)
Max. Marks:70 CHEMISTRY (043)
General Instructions: Time: 3 Hours
Read the following instructions
a) There are 33
carefully.
questions in this question paper with internal choice.
b) Section-A: Consists of 16 multiple choice
c) Section-B: Consists of 5 very short answerquestions and carrying I mark each.
questions and
d) Section-C: Consists of 7 short answer questions and carry 2 marks each.
carry 3
e) Section-D: Consists of 2 case based questions carrying 4 marks each.
Î Section-E: Consists of 3 marks.
long answer questions and carry 5
g) All questions are compulsory. marks each.
h) Use of Log table and calculator are not allowed.

SECTION-A : MULTIPLE CHOICE QUESTIONS

Q! If the concentration of glucose (CoH120%) in blood is 0.9 g
L'. Molarity of glucose in
blood is:
a) 5M
b) SOM
c) 0.005 M d) 0.5 M
Q2 The correct order of increasing energy of atomic orbital is: 1

(a)5p<4f<6s<sd sp<6s<4f<sd
(c)4f<Sp<sd<6s (d)5p<sd<4f<6sf
03 Which of the following represents a correct sequence of electronegativity values :
(a) F> N>0>C (bPSN<0>c
(c) F> N>C>0 () F<N<0<C
Q4 Atomic radius decreases in a period, but after halogens, the atomic radius suddenly
increases. Thus, inert gases have almost highest radius in a period. The explanation for
such an increase is
(anert gases have most stable configuration.
(b) Inert gases do not take part in bonding.
(c) Vander Wall's radius is reported in case of inert gases.
(d) None of these
 Q.5 Which one of the following arrangements of molecules is correct on the basis oftheir

dipole moments?
(a) BF;> NF;> NH1
(b) NE,> BF;> NH;
(c) NH, > BF;> NF3
KH >NF;> BFs
Q.6 Enthalpy of sublimation of a substance is equal to
enthalpy of fusion +enthalpy of vapourisation
b) enthalpy of fusion
c) enthalpy of vapourisation
d) twice the enthalpy of vapourisation
Q.7 Areaction, A+ B C+D+q is found to have a positive entropy change. The reaction
will be
a Possible at high temperature
b) Possible only at low temperature
c) Not possible at any temperature
Possible at any temperature
Q.8 For the reaction, Nz(g) +Oz(g)2NO(g), the production of NO will be favoured by
(a) High pressure. (b) Low pressure.
(c) Presence of catalyst (d) High concentration of N2 and O2

Q.9 For a buffer solution which of the following is true?

(a) pH does not change at all on addition of acid or base
(b)pM change is very little on addition of acid or base
(c) It is a mixture of strong acid with its salt.
(d) It is a mixture of strong base with its salt.
Q.10 In which of the following compounds, 'Mn' exhibits
+6
highest oxidation state?
(b) K;MnO4
(c) MnO2 - (d) MnO
Q.1 What i_ the color of theprecipitate obtained in the laassaigne's test for sulphur?
a) White b) Black
c) Prussian blue d) Blue
Q.12 Hydrolysis of ozonide of But-1-ene gives
(a) Ethylene only a t formaldehyde
(b) Acetaldehyde and
(c) Propionaldehyde and formaldehyde )Acetaldehyde only

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 Instructions for Q.13-Q16
(a) Both Aand Rare true and Ris the correot explanation of A.
(b) Both Aand Rare true and Ris the incorrect explanation of A.
(c) A is true but R is false
(d) A is false but R is true

Q.J3 Assertion (A): The empirical mass of ethene is half of its molecular mass.
Reason (R): The empirical formula represents the simplest whole number ratio of various
2
atoms present in a compound
Q.14 Assertion (A): The bond order of helium is always zero./
Reason (R) :The number of electrons in bonding,molecular orbital and antibonding
molecular orbital is equal.
0l5 Assertion (A): Lithium is astrong reducing agent
Reason(R): Lithium has lowest value of the standard reduction potential
Ol6 Assertion: Among isomeric pentanes, 2, 2-dimethylpropane has highest boiling poni.
Reason: Branching decrease the surface area and intermolecular force of attraction.
SECTION-B:
This section contains 5 questions with internal choice in one question. The following
questions are very short answer type and carry 2 marks each.

the masses of one element

Qi7Iftwo elements can combine to form more than one compound.
number ratio.
that combine witha fixed mass of the other element, are in whole
(a) Name the law which governs this statement?
(b) Give one example related to this law.

2
than the van der Waals forces? and why?
Q18 Define hydrogen bond. Is it weaker or stronger
OR
shape of H;0 molecule is bent
Although both CO2 and H;0 are triatomic molecules, the
moment. 2
while that of CO2 is linear, Explain this on the basis of dipole

ion-electron method:
O.19Balance the following redox reactions by
2

Crp + SOsg) ’ C (ag) + So(a9) (in acidic solution)

sulphur compound
Q.20/n the estimation of sulphur by Carius method, 0.468 g of an organic
afforded 0.668 g of barium sulphate. Find out the percentage of sulphur in the given
Compound.(Mol.mass of BaSO4 =233, S= 32)

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 1443
QDrw
A) Newnan
projetion of ethane
D) Cis and trans
iscomers lex2-ene
of

28
SECTION.C
This seetion contains 7questions with interunl choice in one question, The followim
questions are short answer tyype and carry J marks each.

Q22 Dinitrogen and dihydrogen react with each other to produce anuonia
according to the
following chemical equation: 200 x
(Mol.Mass ofN14)
0Caleulate the mBss of artmonia pbduced it 200 g
dinitrogen reacts with
100 g of dihydrogen.
(ii) Willany of the two reactants remain unreacted?
(üi) If yes, which one and what would be its mass?

Q.23 Aphoton of wavelength 4x 10 mstrikes on metal surface, the work function of the metal
being 2.13 eV. Caleulate
0) The energy of thephoton (oV) (Mass of electron 9.1lx 10kg)
Ai) The kinetic energy of the emission, and
(ii) The velocity of the photoelectron (1 eV= 1.6020 x10-" J).

Q.24 a) Write the Lewis dot structure of NO, NO:

b) Write the hybridization of each C in CH;COOH
c) Write electronic configuration of 0; according to molecular orbital theory.

Q25 a) Write the differences between intensive and extensive properties.

a) Thecquilibrium constant for a reaction is 0.01. What will be the value of AG?
R-8.314 JK mof, T= 300 K, log10-1
Q.26a) Determine number of sigma and pi bond in CH,CH-CHCOOH
b) Write IUPAC name of
CH-CH-CH- CH, 3

COOH COOH

c) Write bond lineformulas for 2,3-Dimethyl butanal.

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 Hec bol Rule
o2A) What are the conditions for any organic compound to be
aromatioF
RHow do you account for the formation of ethane during chlorination of methane? 2

o28 Convert the following (Any Three) 3

(a) Ethyne to benzene
(b) Benzene to m-nitro toluene
(c) Ethanoic acid. to ethane
(d) Propene to I-bromo propane
(e) Phenol to benzene
SECTIOND
The following questions are case -based questions. Each question has an internal
choice and carries 4 (1+1+2) marks each. Read the passage carefully and answer tne
questions that follow

Q29 Read the given passage and answer the questions thatfollow:
Modern periodic table arranges the elements in the increasing order of atomic number.
It has 18 groups and 7 periods. Atomic numbers are consecutive in a period and increases
in group in apattern. Elements are divided into four blocks, s-block, p-block, d-block and
Fblock based on their electronic configuration. 78% of elements are metals, about 20
elements are non-metals and few elements like B, Si, Ge, As are metalloids. Metallic
character increases down the group but decreases along the period from left to right. The
physical and chemical properties vary periodically with their atomic numbers.
Periodic trends are observed in atomic size, ionization enthalpies, electron gain enthalpies,
electronegativity and valence. Oxides of metals are basic, some are amphoteric. Non
metals form acidic oxides, some form neutral oxides. s-block elements are soft, highly
reactive, do not show varíable oxidation states. p-block elements are metals, non-metals as
well as metalloids, show varíable oxidation states, exist as solids, liquids and gases. d
block elements are metals, form-colored ions, show variable oxidation states, have high
melting and boiling ponts. Lanthanoids and actinoids are fblock elements, form colored
ions. All actínoids are radioactive,
/by metallic character increases down the group in Iand Il group?
Group 15 elements have slightly higher ionization enthalpies than group 16" elements 1
in yir respective periods, Why?
Yplain why cations are smaller and anions larger in radii than their parent atoms?
Page 5 of 7
 OR
Which of the following pairs of elements would have a more negative electron gain
enthalpy? For CI? Why?

Q.30 Read the given passage and

answer the questions that follow:
Thermodynamics involve energy changes in chemical reactions and other processes.
Internal energy is total energy stored in a We can specify absolute value of
volume but
substance.
not the absolute value of
internal energy. We can measure only change in
internal energy (AU). Work done on the system is
taken as positive and work done bythe
System is taken as negative. Heat (q) absorbed by the system is +ve
and heat given out D)
system is negative. AU=q+w according to first law of
(enthalpy change) is measured at constant pressure, AUisthermodynamics. AH
measured at constant volune
á) If701 J of heat is absorbed by the
system and 394 J of work is done by the system.
What is value of AU?
1
b) 2 litres of an ideal gas at a pressure of 10 Pertuntilz9
atm expands isothermally into vauum
its total volume is 10 litres. How much heat is
absorbed and work done in the expansion?
c) Derive a relation between Cp and Cv
2
OR
State the first law of thermodynamics and derive its
mathematical expression.
SECTION E
The following questions are long answer type and
carry 5 marks each. All questions
have an internal choice.
Q.31 a)State Pauli's Exclusion Principle.
b Calculate the total number of
angular nodes and radial nodes present in 3p
Show that the circumference of the Bohr orbit for the
hydrogen atom is an
multiple of the de Broglic wavelength associated with the Sps integral 2
electron
around the orbit. 3g2 revolving
d) te the sub-shells which are associated with the n 4?

OR

a) State Photoelectric effect,

 b) State the Significance of y
c) Write electronicconfiguration of Mn (Atomic number of Mn is 25)
2
d) Dual behavior of matter proposed by de Broglie led to the discovery of electron
microscope often used for the highly magnified images of biological molecules and
other type of material. If the velocity of the electron in this microscope is
1.6 x 10° ms, calculate de Broglie wavelength associated with this electron.
(Mass of electron-9.10393x10-3'Kg, Plank constatnt-6.626x 10"Js )
Write its one example of each Lewis acid and Lewis 1.5
Q32 (a) What is Lewis acid base concept?
base.
1.5
drink is 3.8 x 10M.
bthe concentration of hydrogen ion in a sample of soft
What is its pH? (Given : log 3.8 = 0.58)
equilibria from the value of the Kp given:
2
value of Kcfor the following
eFind out the
2NOCI(g) ÷ 2NO(g) + Clh(g) (R=0.0831barLmol-K-)
Kp= 1.8 x 10 at 500K
OR
acid-base pair? Find the possible conjugate 2
conjugate
What is meant by the (any 2)
(a)
following species: HNO2, CN, HCIO4, OH
acid/base pair for the 2

equilibrium?
changes in temperature affect the
(b) How
resultant mixtures:
(c) Calculate the pH of the
Ca(OH)2 + 25 mL of0. IM HCI
10 mL of 0.2M 1.544 )
(logl.5-0.176, log35= 2

effect using suitable example. 1

O33 Kplaininductive
nucleophile, Write its one example. 2
Define nitrobenzene or aniline.
of
Aef Drawresonance structures OR

using suitable example.

Explain hyperconjugation
(a)
radicals, Write its one example. of
2
(b) Define Free
isomerism shown by the following pair
and define the
()Write the name
compounds
() Propanal and Propanone
4-Chlorotoluene
(ii) 2-Chlorotol uene and -ENDOF PAPER