Assam Board Class 11 Question Paper 2022 Chemistry

ASSAM BOARD

QUESTION
PAPER
CLASS 11

Total No. of Printed Pages-11
22E-CHEM

2022

CHEMISTRY

(Theory
Full Marks: 70
Pass Marks: 21

Time: 3 hours

The figures in the margin indicate full marks for the questions

ALLOTMENT OF MARKS

Q. No. l carries l mark each 1x8 8

2x10 = 20
Q. No. 2 carries 2 marks each

Q. No. 3 carries 3 marks each 3x9 27

Q. No. 4 carries 5 marks each 5x3 15

Total 70

/159 Contd.

2)
1. Answer the following
questions (any eign) 1x8-8
f71 SA SE RI ( PITAI
OGI)

a) How many oxygen atoms are present in 2 moics o
Oxygen gas?

b)What is the value of angular momentum 10r
Bohr orbit? rL

c) What is the oxidation state
of K in KO2?
KO K 77 7RIT fPT?

(d) Which of the following molecules shows
isomerism? geometrical

But-1-ene Or/q7 But-2-ene

le) Why are alkali metals not found freely in nature?

( Write the IUPAC name of the
following compound
DM IUPAC

OHC-CH-CH-CoOH

3)
(g) Give one example of electron-deficient covalent
hydride.

h) What is the impact on specific heat of a gas if the
volume of the gas is reduced to half from its
original
volume

What is the hybridization state of each B atom in
BH molecule?
BaHT a1otDI B 7AI RF TTDI ?

Arrange the following in increasing order of their
acidity

B03, In03, Al03

(k)Write two examples of greenhouse gases

State Hückel's rule of aromaticity.

/159 Contd.

4)
2x10-20
2. Answer the following questions (any ten)

2
q)Why does He, molecule not exist?

(b) Define ionization enthalpy. Why is the ionization
enthalpy of nitrogen greater than oxygen althougn the
ionization enthalpy increases from left to rightn
a period? 1+1-2

What is the cause of deviation of real gases from
ideal behaviour? 2

(d) Arrange the following in increasing order 1+1-2

) Br, Cl, I, F (Electron gain enthalpy/ I A)

fi) Al,O3, SiO2, Nag0, Mgo (Acidity/*ra)

e) What property of water makes it useful as a universal
solvent? Why does H,02 behave as bleaching agent?
1+1-2

5)
)Why is acetylene acidic in nature? 2

(9) What are the conditions in terms of entropy and
temperature of an endothermic reaction to be
spontaneous? 1+1-2

h Define electron affinity. Why is electron affinity of
Cl more than F although electron affinity decreases
down the group? 1+1-2

(9 A container contains 2 L of milk. Calculate the volume
of the milk in m. 2

What are the significances of van der Waals'
constants a and b? 1+1=2

k) The pH of a solution at 25 °C is 2. If the pH is to
be doubled, then what will be the hydronium ion
concentration? 2

25 C OTE 9I 4 pH 3 2. 4 pH 7 A 3 7T

[Contd.

6)
(9 Why is CO more dangerous than CO2? 2
COut co f a f7?

(m) Describe one method of removal of permanent
hardness of water.
2

(rWhat is the effect of
the following reaction?temperature on equilibriun 0
2

Na g)+3H2(g)-> 2NH(g) AH =
-92 5 kcal mol

3. Answer the
following questions (any nine) 3x9-27

(a) What do you mean by
the maximum amount limiting reagent? Calculate
of water that can be
when 3-0 g of Ha reacts with formed
29-0 g of Og.
1+2-3
T fP7 3aa TT? 30 g H 29-0 g Og3 He fRT

(b) What is inorganic benzene? How can it be
prepared?

1+2-3

7)
emitted when
(CCalculate the wavelength ofthe radiation
a transition
an clectron in a hydrogen atom undergoes
from fourth energy level to the ground state

ZSM-5. 1+2-3
a What are zeolites? Give two uses of

f ? ZSM-57 ToI A AT

eDefine hybridization. Suggest the structure of TeCl4
in the light of hybridization concept. 1+2-3

Write the chemical reactions involved for detection of
3
nitrogen in an organic compound by Lassaigne's test.

(g)From kinetic gas equation, show that the total kinetic

energy of 1 mole of an ideal gas is RT. 3

PRRT
2

h) What is a polar covalent bond ? Why is NH more polar
than NF3? 1+2-3

/159 Contd

8)
( A person inhales 640 g of On per day. If O2 1s usea
1or converting sucrose (CoH01 ) into CO2 and fau,
how much sucrose is consumed by the body per day
and what will be the heat evolved? Given, AcH 10r

sucrose =-5645 kJ mol 3
4713 iRs 640 g o, BRE 7I zA COTRAA O2
(C12H22011) CO2 T Hoofada atA a4

AcH=-5645kJ mol

i) Balance the following redox reaction 3

Mn04laq)+Br (aq) > Mn2* (ag) +Br2(liq)

(k) What happens when-

(i) Mg is burnt in air;
Mg FR P1 R
7) quicklime is heated with silica;

ii) chlorine reacts with slaked lime? 1+1+13

Discuss the mechanism involved in Markovnikov's
rule. 3

10)
ruie
Hund's
State Pauli's exclusion principle and
electronic
of maximum multiplicity. Write the
following
configuration of Cr and Cu. Arrange the
orbitals in increasing order of their El
1+1+2+1=5

6s, 5d, 4f, 6p

(d) Complete the following reactions 1x5-5

(i) CH3l+ Na Dry ether

OH
(ü) CHg-CH2-H-CH Conc.
nc H2SO4,
Had04,p
373 K

i) CHg-CH=CH2 1) O3/CHClh
2) Zn-H,0

(iv) +Cl2 FeCl3?

Conc.
(o)
() Conc. HNO HS04

11)
(e) Define
standardstandard enthalpy of formation. Calculate the
enthalpy of
given data formation of ethane from the
1+4-5

C(graphite)+O2t
O2g)>CO,(g); A,H° =-394 kJ mol

Hag+O2(g)->
2 H,0; A,H" -286 kJ mol
=

CaHsel+02g)-2C02(g)+3H,00; A,H° =-1560 mol kJ

/159 22C