XII.CHEMISTRY CBSE 2015 MODEL PAPER SET -1
SAMPLE QUESTION PAPER
CHEMISTRY (043)
CLASS- XII - (2014-15)
: Time Allowed: 3 Hrs Maximum Marks 70
General
Instructions:
1. All questions
are compulsory.
2. Question No.
1-5 are very short answer questions and carry 1 mark each.
3. Question No.
6-10 is short answer questions and carries 2 marks each.
4. Question No.
11-22 is also short answer questions and carries 3 marks each.
5. Question No.
23 is value added questions and carry 4 marks.
6. Question No.
24-26 carry 5 marks
7. Use log
tables if necessary, use of calculators is not allowed.
1. Why a Schottky
defect is formed when calcium chloride is added to silver chloride crystal?
2. Give the IUPAC
name of .
CH3-CH(OH)-CH(Cl)-COOH
3.Which compound give
faster electrophilic substitution reaction between Benzene and toluene.explain.?
4. Draw the structure
of N-N, dimethyle butanamine
5. Why the process of
adsorption is always exothermic?
6. Define (i)
colligative properties (ii) vant hoff factors (iii) henery Law
OR
5% Aqueous solution
of glucose is isotonic with 0.897% solution of urea . find out molecular mass
of urea.?
7. what do you mean
by activation energy. How a catalyst increase the rate of reaction.?.
8. Write the
chemical reaction for the preparation of KMnO 4.
9. (i)Aniline can’t
be prepared by Gabriel pthalamide reaction.?
(ii) Phenol show acidic character .How?
10. Write the
following name reaction
(i)
Halloform reaction
(ii)Clemmenson
reaction
11. Write a note on
the following with an example each:
(i).
Hardy scheulze rule
(ii).
Dialysis
(iii)
Shape selective catalysis.
12. Write a note on:
(i
)Write roll of iodine in the isolation of Zirconium.
(ii).
What is roll of NaCN in the froath fotation process
(iii)Write
the name of process used for extraction of Ni.
13. Answer the
following:
i.Ni0.98
O1.OO is a compound in which Ni is present with +2 and +3 oxidation
state. Find
out percentage of both form of nickel.
ii.
Why density decrease during Schottky defect.
OR
(i)
Atom X present at the corner of unit cell while atom y
is at the center of each face. Find out empirical formula of the unit cell.
(ii)
(iii)
What do you mean by F-center.?
14. 19.5 gm of CH 2FCOOH
is dissolve din 500 gm of water and then F.P depressed by 1 0
C.Using
Kf = 1.86 find out its Vant Hoff factor.
15 If 90% of a reaction complete in 5 min .Find
its half life period.
16. Give reasons:
(i)
Give example of hexadentate Legends (ii) What id
hydrate isomerism give example.
(ii).
Write IUPAC name of the following compound
K 4 [Fe (CN) 6(NH3.)]
17 (i) Why Cr 2+
is reducing and Mn 3+ is oxidizing where both has d 4
configuration.
(ii)What is Lanthanides contraction?
Explain reason?
(iii)Why Mn 2+ is stable then
Mn 3+?
18. (i) Iproniazole
is used as a tranquillizers.
(ii) Write composition of Dettol.
(iii)What is harmfull effect of pain
killer in excess.
19. Write the formula of main
product formed in the following chemical reactions.
(i) CH3Br + AgF
(ii) CH3CH2Br
+ Nal
(iii) Arange the Acidity order of
oxo acid of chlorine is
HOCl , HOClO , HOClO2 ,
HOClO3
20.
Give reasons
i.
HI is better reagent than HBr for cleavage of ether.
ii.
Highly branched carboxylic acids are less acidic than unbranched acids.
(iii)Aniline
does not give friedal craft reaction.?
21. Differentiate the
following pair of polymers based on the property mentioned against each.
(i)
Novolac and Bakelite (structure)
(ii)
Buna-s and Terylene (intermolecular forces of attraction)
(iii)Write
monomer structure of nylon -6,6.
22. Give the reason
for the following:
a.
Drow the structure of H3 PO4
AND H2 S2
O8
b.
Why Pcl 5 is ionic in solid state.
23. Sara went to market to buy fruits and
vegetables. The vendor put the fruits and
Vegetables
in the polythene bag but Sara ask
the vendor to put the things in the jute
Bag
which he Carried with him. Now answer the following question
a.
Why did Sara refuse to use polythene bags?
b.
As a student of chemistry why would you advocate the
use of jute bags instead of
polythene
bags? Which values are promoted through the use of jute bag?
c.
Suggest two activities to promote these activities
24. Convert the
following:
a. Toluene to benzaldehyde
b. Ethanal to but-2-enal.
(
c) The following chemical reaction is
occurring in an electrochemical cell.
Mg(s) + 2 Ag+ (0.0001 M) Mg2+ (0.10M) + 2 Ag(s)
The electrode values are
Mg2+ / Mg = – 2. 36 V
Ag+ / Ag = 0.81 V
For
this cell calculate EMF of the cell.
OR
(i)
Write a suitable reaction for the preparation of
t-butylethyl ether from alky halide and sodium alkoxide.
(ii)
Write mechanism of dehydration of ethyl alcohol in
presence of strong acid. And what happen if this reaction is carried out at Law
temperature?
(iii)
What is the order of the
reactions?
(iv) What are the
units of rate constant k for Zero order?
(v) Give the
relationship between k and t ½ (half life period) for Zero order reaction
25. . A
mixed oxide of iron and chromium FeOCr2O3 is fused with
sodium
Carbonate in the presence of air to
form a yellow coloured compound (A).
On acidification the compound (A)
forms an orange coloured compound (B),
Which is a strong oxidizing agent?
Identify
(i)
The compounds (A) and (B)
(ii)
Write balanced chemical equation for each step
OR
Heptanes and octane
form an ideal solution at 373 K, The vapour pressures of the pure liquids at
this temperature are 105.2 KPa and 46.8 KPa respectively. If the solution
contains 25g of heptanes and 28.5g of octane, calculate
(i) Vapour pressure
exerted by heptane
(ii) Vapour
pressure exerted by solution
(iii) Mole fraction
of octane in the vapour phase.
26. Account for the following facts
(a) State kohalraush Law..
(b) Write chemical; reaction for the lead storage battery during
discharge.?
(c)
Limitation of Henery law.
(d)Faraday
second law of electrolysis.
(e)Define
Molar conductivity.
OR
a)
Can lanthanum ion exist in +4 oxidation state? Justify.
b)
Why europium (II) more stable than cerium (II).
c)
write advantage of fuel cell.
d) define electrode potential
e)State Faraday first law of electrolysis
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