CHEMISTRY SAMPLE PAPER - II CLASS - XII

CHEMISTRY SAMPLE PAPER - II
CLASS - XII

Time : Three Hours

General Instructions
1.
All questions are compulsory.
2.
Question nos. 1 to 8 are very short answer questions and carry one mark each.
3.
Question nos. 9 to 18 are short answer questions and carry two marks each.
4.
Question nos. 19 to 27 are also short answer questions and carry three marks each.
5.
Question nos. 28 to 30 are long answer questions and carry five marks each.
6.
Use log tables if necessary. Calculators are not allowed.

Give IUPAC name of the following organic compound

1.

Max. Marks : 70

What are the physical states of dispersed phase and dispersion medium of froth?

2.

3.

Write the balanced equation for complete hydrolysis of XeF6

Write the structure of :
4 - methyl pent - 3 - en - 2 - one

4.

1

1

1

1

A compound contains two types of atoms - X and Y. It crytallises in a cubic lattice with atom X at the corners of the
unit cell and atomsY at the body centres. What is the simplest possible formula of this compound?
1

5.

6.

What is the Van’t Hoff factor for a compound which undergoes tetramerization in an organic solvent?

An ore sample of galena (PbS) is contaminated with zinc blende (ZnS). Name one chemical which can be used to
concentrate galena selectively by froth floatation method.
1

7.

1

8.

Predict the shape of CIF3 on the basis of VSEPR theory.

Ethylene glycol (molar mass = 62 g mol¯ 1) is a common automobile antifreeze. Calculate the freezing point of a
solution containing 12.4g of this substance in 100 g of water. Would it be advisable to keep this substance in the car
radiator during summer?
Given : Kf for water = 1.86K kg/mol
Kb for water = 0.512K kg/mol
2

9.

1

k
Consider the reaction A → P. The change in concentration of A with time is shown in the following plot:

10.

(18)

(i) Predict the order of the reaction.
(ii) Derive the expression for the time required for the completion of the reaction.

Free energies of formation

11.

of MgO(s) and CO(g) at 1273 K and 2273K are given below

(MgO(s)) = - 941 kJ/mol at 1273K

(MgO(s)) = - 314 kJ/mol at 2273K

(CO(g))

= - 439 kJ/mol at 1273K

(CO(g)) = - 628 kJ/mol at 2273K
On the basis of above data, predict the temperature at which carbon can be used as a reducing agent
for MgO(s).
2

Name the two components of starch. How do they differ from each other structurally?

12.

(a) What changes occur in the nature of egg proteins on boiling?
(b) Name the type of bonding which stabilizes α -helix structure in proteins.

13.

2

2

14.

Describe the mechanism of the formation of diethyl ether from ethanol in the presence of concentrated sulphuric
acid.
2

15.

Complete and name the following reactions:

2

16.

Give chemical tests to distinguish between compounds in each of the following pairs:
(i) Phenol and Benzyl alcohol
(ii) Butane-2 -ol and 2 Methyl propan - 2- ol

Predict, giving reasons, the order of basicity of the following compounds in (i) gaseous phase and (ii) in aqueous

17.

solutions

OR
Account for the following:
(a) Aniline does not undergo Friedel Crafts alkylation
(b) Although - NH2 group is an ortho and para-directing group, nitration of aniline gives alongwith ortho & para-
derivatives meta-derivative also.

Give reasons for the following :
(a) At higher altitudes, people suffer from a disease called anoxia. In this disease, they become weak and cannot
think clearly.
(b) When mercuric iodide is added to an aqueous solution of KI, the freezing point is raised.
2

18.

2

2

An element X with an atomic mass of 60g/mol has density of 6.23g cm-3. If the edge length of its cubic unit cell is
400 pm, identify the type of cubic unit cell. Calculate the radius of an atom of this element.
3

19.

(19)

20.

Write names of monomer/s of the following polymers and classify them as addition or condensation polymers.
(a) Teflon
(b) Bakelite
(c) Natural Rubber
3

(a) Give the IUPAC name of :
[Cr Cl2 (H2O)4] Cl
(b) Give the number of unpaired electrons in the following complex ions:

21.

(c) Name the isomerism exhibited by the following pair of coordination compounds:

Give one chemical test to distinguish between these two compounds.

22.

Explain the following observations:
(a) Ferric hydroxide sol gets coagulated on addition of sodium chloride solution
(b) Cottrell’s smoke precipitator is fitted at the mouth of the chimney used in factories.
(c) Physical adsorption is multilayered, while chemisorption is monolayered.

Account for the following:
(a) Chlorine water has both oxidizing and bleaching properties.
(b) H3PO2 and H3PO3 act as as good reducing agents while H3PO4 does not.
(c) On addition of ozone gas to KI solution, violet vapours are obtained.

23.

The decomposition of N2O5(g) is a first order reaction with a rate constant of 5 x 10-4 sec-1 at 45o C. i.e. 2N2O5 (g)
4NO2 (g) + O2 (g). If initial concentration of N2O5 is 0.25M, calculate its concentration after 2 min. Also
calculate half life for decomposition of N2O5 (g).

24.

(b) For an elementary reaction

the rate of appearance of C at time ‘t’ is 1.3 x 10-4 mol l-1 s-1.
Calculate at this time
(i) rate of the reaction.
(ii) Rate of disappearance of A.

(a) Which of the following two compounds would react faster by SN2 path way : 1 - bromobutane or
2 - bromobutane and why.?
(b) Allyl chloride is more reactive than n - propyl chloride towards nucleophilic substitution reaction. Explain why?
(c) Haloalkanes react with KCN to give alkyl cyanide as main product while with AgCN they form isocyanide as
main product. Give reason.

25.
Give reasons for the following:
(a) CN¯ ion is known but CP¯ ion is not known.
(b) NO2 demerises to form N2O4
(c) ICl is more reactive than I2

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Design of Question Paper Mathematics Class XII

Design of Question Paper
Mathematics - Class XII

Time : 3 hours

Weightage of marks over different dimensions of the question paper shall be as follows :

Weightage to different topics/content units


Max. Marks : 100

Topics
Relations and functions
Algebra
Calculus
Vectors & three-dimensional Geometry
Linear programming
Probability

Marks
10
13
44
17
06
10
100

Weightage to different forms of questions

Forms of Questions

Very Short Answer questions (VSA)
Short answer questions (SA)
Long answer questions (LA)
Total

(1)

Class XII
MATHEMATICS
Blue-Print I

(2)

Sample Question Paper - I
MATHEMATICS
Class XII

Time : 3 Hours

General Instructions

All questions are compulsory.

SECTION - A

Which one of the following graphs represent the function of x ? Why ?

1.

y

y

x

x

(a)

(b)

What is the principal value of

2.

2π 
2π 

−1 
cos −1  cos
 + sin  sin
 ?
3 
3 



3.

A matrix A of order 3 × 3 has determinant 5. What is the value of | 3A | ?

4.

For what value of x, the following matrix is singular ?

5 − x
 2


x + 1
4 


Find the point on the curve y = x 2 − 2 x + 3 , where the tangent is parallel to x-axis.

5.

What is the angle between vectors a & b with magnitude √3 and 2 respectively ? Given a . b = 3 .

6.


Cartesian equations of a line AB are.

7.

2x −1 4 − y z + 1
=
=
2
7
2

Write the direction ratios of a line parallel to AB.

8.

Write a value of


(x )dx

3 log x


Write the position vector of a point dividing the line segment joining points A and B with position vectors a & b
externally in the ratio

9.

ˆ j
1 : 4, where a = 2 i + 3ˆ + 4k and b = − iˆ + ˆ + k
j ˆ

3 − 1
 2 1 4


If A = 
 and B = 2 2 
 4 1 5
1 3 



10.

Write the order of AB and BA.

Show that the function f : R → R defined by f (x ) =

11.

inverse of the function f.

OR
Examine which of the following is a binary operation

(i)

SECTION - B

2x −1
, x ∈ R is one-one and onto function. Also find the
3

a+b
, a, b ∈ N
2

a*b=

a+b
, a, b ∈ Q
2

a*b =

(ii)

for binary operation check the commutative and associative property.

Prove that

12.

 63 
5
3
tan −1   = sin −1   + cos −1  
 16 
 13 
5


13.

Using elementary transformations, find the inverse of

2 − 6
1 − 2 



OR

Using properties of determinants, prove that

− bc

b 2 + bc c 2 + bc

a 2 + ac

a 2 + ab b 2 + ab

c 2 + ac = (ab + bc + ca )3

− ac

− ab

Find all the points of discontinuity of the function f defined by

14.

x + 2,
x ≤1
f (x) = x − 2, 1 < x < 2
0,
x≥2

p q
If x y = (x + y )

15.

p +q

, prove that

dy y
=
dx x

OR

 1 + x2 + 1 − x2 
dy
−1
 , 0 < | x | <1
, if y = tan 
Find
dx
 1 + x2 − 1 − x2 



Evaluate

16.

(x + 1)(x
∫ (x + 3)(x

2

2

) dx
− 5)

+4

2

2

17.

A water tank has the shape of an inverted right circular cone with its axis vertical and vertex lower most. Its semi-

−1
vertical angle is tan   . Water is poured into it at a constant rate of 5 cubic meter per minute. Find the rate at

which the level of the water is rising at the instant when the depth of water in the tank is 10m.

Evaluate the following integral as limit of sum

18.

Evaluate

19.

20.

Find the vector equation of the line parallel to the line

1
2

x −1 3 − y z + 1
=
=
and passing through (3, 0, –4). Also
5
2
4

(5)

find the distance between these two lines.

In a regular hexagon ABC DEF, if AB = a and BC = b , then express CD, DE, EF, FA, AC, AD, AE and CE

21.

in terms of a and b .

A football match may be either won, drawn or lost by the host country’s team. So there are three ways of
forecasting the result of any one match, one correct and two incorrect. Find the probability of forecasting at least
three correct results for four matches.
OR
A candidate has to reach the examination centre in time. Probability of him going by bus or scooter or by other

22.

1
1
3 1 3
, , respectively. The probability that he will be late is and respectively, if he
4
10 10 5
3
travels by bus or scooter. But he reaches in time if he uses any other mode of transport. He reached late at the
centre. Find the probability that he travelled by bus.

means of transport are

SECTION - C

23.

Find the matrix P satisfying the matrix equation

 2 1   − 3 2  1 2 
3 2 P  5 − 3 = 2 − 1


 
 

Find all the local maximum values and local minimum values of the function

24.

f (x ) = sin 2 x − x,

−

OR

π
π
<x<
2
2

A given quantity of metal is to be cast into a solid half circular cylinder (i.e., with rectangular base and semicircular
ends). Show that in order that the total surface area may be minimum, the ratio of the length of the cylinder to the

diameter of its circular ends is π : (π + 2 ).

Sketch the graph of

25.

| x − 2 | +2, x ≤ 2
f (x ) =  2
x>2
 x − 2,

What does the value of this integral represent on the graph ?

Evaluate

Solve the following differential equation 1 − x 2

26.

(

) dy − xy = x , given y = 2 when x = 0
dx

(6)

2

27.

Find the foot of the perpendicular from P(1, 2, 3) on the line

x−6 y−7 z−7
=
=
3
2
−2

Also obtain the equation of the plane containing the line and the point (1, 2, 3)

28.

Let X denote the number of colleges where you will apply after your results and P(X = x) denotes your probability
of getting admission in x number of colleges. It is given that

if x = 0 or 1
kx

P(X = x ) = 2kx
if x = 2
,
k (5 − x ) if x = 3 or 4


k is +ve constant

(a) Find the value of k.
(b) What is the probability that you will get admission in exactly two colleges?
(c) Find the mean and variance of the probability distribution.

OR
Two bags A and B contain 4 white 3 black balls and 2 white and 2 black balls respectively. From bag A two balls
are transferred to bag B. Find the probability of drawing
(a) 2 white balls from bag B ?
(b) 2 black balls from bag B ?
(c) 1 white & 1 black ball from bag B ?

29.
A catering agency has two kitchens to prepare food at two places A and B. From these places ‘Mid-day Meal’ is
to be supplied to three different schools situated at P, Q, R. The monthly requirements of the schools are respec-
tively 40, 40 and 50 food packets. A packet contains lunch for 1000 students. Preparing capacity of kitchens A
and B are 60 and 70 packets per month respectively. The transportation cost per packet from the kitchens to
schools is given below :

How many packets from each kitchen should be transported to school so that the cost of transportation is mini-
mum ? Also find the minimum cost.

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