SAMARITANS SENIOR SECONDARY SCHOOL,

HOSHANGABAD(M.P.)
SESSION - 2020-21
Subjective Assessment - 1
Class - XII
General Instructions : -
1.Students must write answers in 50 pages test copy.(separate for all subjects)
2. Students must be fair in writing answers .
3.On the first page of all test copies parents have to give declaration and sign it.
" I hereby declare that my child has attempted question paper himself or herself."
Parent's signature
4.Parents must become invigilator for the child.
5.Try to manage time and complete within 3 hrs.

Time : 3 Hrs Subject – Chemistry M. M. 70

Questions 1-14 ( 1 Mark each), 15 ( Case -based – 7 Marks),

16-20 ( 2 Marks each), 21-28 (3 Marks each), 29-31(5 Marks each).

SECTION-A

Note: Q. 1 to Q. 4 are one word answers.

1.Write the IUPAC name of the following compound:

( CH3) 3CCH2Br.

2.Draw the structural formula of 2-methylpropan-2-ol molecule.

3.The general electronic configuration of the transition elements is..

4. Write Freundlich adsorption isotherm equation at low pressure.

Note: Q. 5 to Q. 9 are multiple choice questions.

5. Tyndall effect is due to

a) electric charge b) scattering of light

c)absorption of light d) none of these.

6.Which of the following halogen shows only negative oxidation state?

a) Chlorine b) Bromine

c) Fluorine d) Iodine

7.Unit of a rate of a reaction is

a) mol-1 L s-1 b) mol L s-1

c) mol2 L s-1 d) mol L-1 s-1

8. The e. m. f. of the cell :

Cu (s) | cu2+ ( 1 M) || Ag+ ( 1 M) | Ag

Is 0.46 V. The standard reduction potential of Ag+/Ag is 0.80 V.

The standard reduction potential of cu2+/cu is

a) – 0.34 V b) 1.26 V
b) -1. 26 V d) 0.34 V

9. The Colligative properties of a dilute solution depends on

a) nature of solute b) nature of solvent

c) number of particles of solute d) molecular mass

For question number 10 to 14, two statements are given—one labelled as

Assertion ( A) and the other labelled as Reason ( R). Select the correct

To these questions from the codes (A), (B), (C), (D) as given below.

(A) Both assertion (A) and (R) are correct statement, and reason
(R) is the correct explanation of the assertion (A).

(B) Both assertion (A) and reason (R) are correct statements. But reason

(R) is not the correct explanation of the assertion (A).

(C) Assertion (A) is correct, but reason (R) is wrong statement.

(D) Assertion (A) is wrong, but reason (R) is correct statement.

10. Assertion: Ozone is a powerful oxidising agent in comparison to O2.

Reason: Ozone is Dimagnet but O2 is paramagnetic.

11. Assertion: Sodium chloride used to clear snow on the roads.

Reason: The alkaline solution of pot.dichromate contains CrO42- ions.

12. Assertion: [ Ni( Co)4 ] is Dimagnet complex.

Reason: It involves SP3 hybridisation and there is no unpaired electrons.

13.Assertion: KCN reacts with methyl chloride to give methyl Isocyanide.

Reason: CN- is an ambident Nucleophile.

14.Aeesrtion: Nitration of Chlorobenzene leads to the formation of

m-nitrocholrobenzene.

Reason: --NO2 group is directing group.

SECTION- B

15. Read the passage and answer the following questions.

Colloidal particles always carry an electric charge which maybe either

Positive or negative. Ex. When AgNo3 is added to KI solution, a negatively

Charged colloidal solis obtained. The presence of equal and similar

Charges on colloidal particles provide stability and if somehow charge

Is removed, coagulation of sol occurs. Lyophobic sols are readily coagulated

As compared to lyophilic sols.

Lyophobic sols are positively or negativity charged. These

are coagulated by electrolytes. Opostively charged ions are most effective for

Coagulation. For As2S3 sol, out of 0.1 M AlCl3, 0.1 M MgCl2 and 0.1 M NaCl

Solution, 0.1 M AlCl3 is most effective. The number of particles produced by

Electrolyte in aq. Solution depends upon degree of ionisation.

I) What is the reason for the charge on sol particles?

II) Why the process of equal and similar charge on colloidal
Particles provide stability?
III) Why is negatively charged sol is obtained on adding AgNO3
To KI solution.
IV) Name one method by which coagulation of lyophobic
Sol can be carried out?
V) Out of kI or K2SO4, which electrolyte is better in the coagulation
Of positive sol.
VI) Which sol is obtained when AgNo3 is added to KI solution?
VII) The molar mass of electrolytes determined with the help of
Colligate property is abnormal, why?

SECTION-C
16. Consider the rate equation Rate = k [ A]n
What is the change of rate that occurs on doubling the
Concentration of A, when
i) n = 0 ii) n =1 iii) n= 2 ?

17.Expalin, why

a) O3 acts as a powerful oxidising agent.

b) why are elements of group 18 known as noble gases?

Or

a) Why does NH3 acts as a Lewis base?

b) Bond angle in NH4+ is more than that in NH3.

18. How will you distinguish between:

I) Metallic conduction and electrolytic conductance?

ii) strong and weak electrolytes?

19. The reaction: 2A+ B  C+D has the rate equation:

Rate = k [ A]x [ B] y

I) What is the Molecularity of a reaction?

II) Order of reaction when B is present in large excess.

20. What happens when:

a) ethanol is treated with methyl magnesium bromide and the

Product is hydrolysed.

c) Phenol is treated with zinc dust.

d) Methoxyethane is treated with excess of HI.
Or
Illustrate the following reaction giving a chemical equation
For each:
I) Kolbes reaction.
II) Williamson’s synthesis.

SECTION-D

21. How will you convert the following:

I) propan-2-ol to propanone.
 II) Phenol to 2,4,6-tribromophenol.

22. A) state Henry’s law. What is the effect of temperature on the

Solubility of gas in a liquid?

B) State Raoults law for the solution containing volatile

Components. What is the similarity between Raoults law
And Henry’s law.
Or
Describe a method to determine the osmotic pressure of
A solution. How does it help in calculating the molar mass
Of the solute?

23. Zinc rod is dipped in 0.1 M solution of ZnSO4. The salt is

95℅ dissociated at this dilution at 298K.calculate the electrode

Potential given that E¢ ( Zn2+|Zn) = - 0.76 V.

24.A) Name the transition elements which shows only +3

Oxidation state.

B) what is lanthanoid contraction?

Or

A) Give the general electronic configuration of d- block

Elements.
B) out of Fe2+ and Fe3+ , which is more paramagnetic
And why?

25. A) How are following conversation be carried out:

I) Benzene to Diphenyl.

II) Aniline to Chlorobenzene.

B) why is tricholorometahne stored in dark coloured bottles?

Give reason with related equation.

26. Write the IUPAC name of the following:

I) [ Cr( NH3) 3 ( H2O) 3] Cl3

II) K3 [ Al ( C2O4) 3]

III) [ Co ( NH3) 5 ( CO3) ] Cl

 27.Using crystal field theory, write the number of unpaired
Electrons in octahedral complexes of Fe3+ in the
Presence of
a) Weak field ligand.
b) Strong field ligand.

28. Most important chemical reactions of Haloalkanes are

Their substitution reactions.

a) What is SN1 reaction?

b) Arrange the four isomeric bromobutanes in the
Increasing order of their reactivity towards
SN1 reaction.
SECTION- E

29.A)what are Interhalogen compounds? Write with

Examples.

B) what are noble gases? Why are they named so?

Account for the fact that noble gases exhibit low

Chemical reactivity.

Or

A) Account for the following:

I) NH3 acts as a Lewis base.
II) PCl3 fumes in moist air.
III) Flourine shows only -1 oxidation state.

B) I) suggest any two flourides of xenon.

II) write a method to prepare any one of the above

Mentioned xenon fluorides.

30. Write short notes on the following:

I) Sandmeyers reaction

II) Friedel- Crafts Alkylation

III. Anti-Markovnikov rule.

Or

a) A hydrocarbon A ( C4H8) is added with HBr in

 Accordance with markovnikov rule to give compound
B which on hydrolysis with aq. Alkali forms tertiary
Alcohol C ( C4H10O). Identify A, B, C.
B) Convert Chlorobenzene into phenol.

31.A) write down the unit of rate constant for zero

Order reaction.

B) Derive the rate equation:

K = 2.303/t log a/a-x

For first order reaction and establish the relationship

Between half life period and it’s rate constant.

Or

I) What is the difference between Molecularity

And order of reaction.
II) For a first order reaction, half life period t1/2 is
100 seconds. How long will it take for the reaction
To complete 75℅ ?

//////////////////////////////////////////////////////////
MM 70 SUBJECTIVE EXAM (Physics) Class 12th TIME- 3hrs

There are 33 questions in this paper. All questions are compulsory.

Section A (Q. No 1 to 14 carry 1 mark each.)

1. What is SI unit of Magnetic flux?

2. Angle of dip at a place on earth is 30 degrees and Magnetic Field is 0 4 T. What is Horizontal
component of Magnetic Field?

3. Draw graph between capacitive reactance and frequency.

4. A point charge +q is placed at origin. How much flux is associated with the entire YZ plane?

5. Work function of a metal surface us 3 eV . Find threshold frequency.

6. A charge particle enters in a region of non uniform magnetic field with Kinetic Energy of 5 eV. How its
kinetic energy will change in magnetic field ?

7. Resistance of Galvanometer is 100 ohm and Ig is 10 mA. What will be the resistance of a voltmeter of
range 1V ?

8. The balancing length for cell of EMF 4V is 50 cm in a potentiometer experiment. What is balancing
length for another cell of EMF 5 V ?

9. If the SI units of electric permittivity and Magnetic permeability are x and y respectively. Write SI unit
of velocity in terms of x and y.

10. Find energy equivalent in eV corresponding to mass of 0.4 a.m.u.

11. Assertion (A): Gauss theorem can be applied only for a closed surface.

Reason (R):Electric flux can be obtained passing from an open surface also.

12. Assertion (A):In practice electric dipole oscillates about external electric field.

Reason (R):Restoring torque acts on dipole because of its inertia.

13. Assertion (A):Two non ideal batteries are connected in parallel with same polarities on same side.
The equivalent EMF is smaller than either of two batteries.

Reason(R):When two non ideal batteries are connected in parallel their equivalent internal resistance
is smaller than either of two internal resistances.

14. Assertion (A):The path of charged particle in uniform magnetic field can not be parabola.

Reason (R): For parabolic path acceleration should be constant.

15. Consider a pure inductor of L = 20 mH that is connected to voltage source of V=10 sin200t where V is
in volts and t in sec.

(A) What is phase difference between V and I?

(B)What is instantaneous power?

(C) What is value of reactance?

(D) What is Irms?

(E) Draw Phasor diagram.

16. A point charge +q is fixed at origin. Another point charge -q is released from very large distance on X
axis. Neglect gravity everywhere.

(A) Find net force on moving charge at x=a.

(B)Find net force on +q at this point.

(C) What is net force on +q at every instant.?

(D)What is the direction of dipole moment of this system?

(E)What is the magnitude of dipole moment of system at x=a?

Section C

(Q. No 17 to 25 carry 2 marks each.)

17. Define Electric Potential due to point charge

18.Draw graph between Kmax of photoelectrons and frequency of incident radiation. Also find its slope.

19.Draw phasor diagram for circuit containing capacitor with a.c. source.What is its reactance?

20.Derive expression of energy stored in a capacitor .

21.How to convert a Galvanometer in an Ammeter ?

22.Define equipotential surface. Draw equipotential surfaces for a dipole.

23.What is Wheatstone’s bridge? Find its balanced condition from kirchhoff's laws.

24.Define Self Inductance. Derive an expression of self inductance of a long solenoid.

25.Two point charges +2q and -q are situated at (a,0) and (-a,0) respectively. Find locus of points where
potential due to system is zero.

Section D

(Q. No.26 to 30 carry 3 marks each.)

26.Derive electric field due to small dipole in (1)axial and (2) transverse position.

27.From Biot - Savart law derive expression of Magnetic Field due to current carrying circular coil at a
point on its axis. Plot a graph showing variation of Magnetic Field with axial distance.

28.Explain principle of meter bridge?

29.Using Bohr's Theory of hydrogen atom derive an expression of energy of electron in nth state. Also
find wavelength of 4th line in Balmer Series.

30.A small dipole of dipole moment p is placed at origin pointing positive X direction. Find Electric Field
and Potential due to dipole at point with coordinates (0,a,a).

Section E

(Q. No.31 to 33 carry 5 marks each).

31. (1) What is Ampere's circuital law?

(2) Find Magnetic Field due to long solenoid using Ampere's law.

(3) The horizontal component of earth's magnetic field and total magnetic field are 0.5G and 0.8G
respectively .Find angle of dip and Vertical component of field.

32. (1) State Gauss theorem in electrostatics.

(2) Using Gauss theorem find electric field due to infinite and uniform line charge.

OR

(1) Find electric field due to uniformly charged thin non conducting sheet.
(2) An electron of charge e is moving along straight line and parallel to this thin sheet by distance
d. Find work done by electric field on electron.

33. (1) Explain working principle of a Potentiometer.

(2) Compare EMF of two cells using Potentiometer.

(3) Why Voltmeter can not be used to measure EMF of a cell.?

OR

(1) What is Geiger-Marsden Experiment.?

(2) Plot graph showing no of alpha particles scattered against angle of scattering.
(3) What does this graph say about size of Nucleus?