CBSE CHEMISTRY XII- SET-3 - 2017 MODEL SET
CLASS - XII
CHEMISTRY MODEL
PAPER – (043)—2017
SET-3
Time : Three
hour
Max. 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.
Q1. What are
antifertility drugs .give example? 1
Q2. Why pine oil is
added in froath flotation process? 1
Q 3. Write the
balanced equation showing disproportationation reaction of pyrophosphoric acid. 1
Q4. Write IUPAC name
of the following compound C6H5CH(CHO)COOH 1
Q5. 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 thiscompound?
1
Q6. What happen if we put R.B.C in 1% Nacl
aqueous solution.. 2
Q 7. (i)Write the
name of procesds which can be used for the purification of galena. 2
(ii) Define what is leaching .
Q 8.Drow the
structure of XeF 4 and HclO3.
2
Q9. Urea (molar mass = 60 g
mol¯ 1) is present in a solution having osmotic pressure of 4.12atm. Calculate
the weight of urea present in it if the room temperature is 270 c.
2
Q 10. Define first
order rate constant and half life period.
Q11.(i)define molar
conductivity. How it change with change in temperature..? .
(ii)write two advantage of fuel cell.. 3
Q12. (i)Why sleeping
pills contains tranquilizers..
(ii)Give chemical equation when glucose
react with hydroxyl amine.
(iii)What do you mean by property
dextrorotatory nature of glucose.? 3
Q13. (i) What is
Glycosidic linkage.give example.?
(ii) Define alpha helix and beta
pleated structure of protein. 3
Q14. (i)Describe the
mechanism for the formation of ethoxy ethane from ethyl alcohol.
(ii)Give a mechanisn of reaction when
propene react with hydrochloric acid? 3
Q15. Write short
notes on the following name reaction : 3
(i) Etard reaction
(ii)Garbriel pthalamide reaction
(iii)Finklestein reaction.
Q16. (a)Give chemical
tests to distinguish between compounds in each of the following pairs:
(i) Methyl alcohol and Ethyl alcohol
(ii) Metanoic acid and Ethanoic acid
(b)Aniline does not give friedal craft reaction.explain? 3
Q 17. Predict, giving
reasons, the order of the following
compounds in
(i) HCHO,CH3CHO.CH3COCH3,CH3COCH2CH3 (Nucleophilic addition reaction)
(ii) CH3NH2 ,(CH3)2NH ,(CH3)3N and C2 H5 NH2,
(C2 H5)2 NH
, (C2 H5 )3N(Basicity) 3
OR
Account for the following:
(a) Aniline cant be prepared by
garbriel pthalamide reaction
(b) 20 Amine is more basic then 30
Amine.Explain?
Q 18. (i) At higher
altitudes, people suffer from a disease called anoxia. In this disease, they
become
weak and cannot think clearly.why.?
(ii) Write the name of defeciency desease cause by vitamins C&B12.
(iii)Define what is
electrodialysis. 3
Q19.(i) An element X
with an atomic mass of 40g/mol has density of 3.01 g cm-3. If
the edge length of
its cubic unit cell is 400 pm,. Calculate
the radius of an atom of this element. Considerinf
it FCC.
(ii) Define what is feromagnectic
substances.
Q20. Write names of
monomer/s of the following polymers and give important uses..
(a) Melamine formaldehyde polymers (b) Bakelite (c) Nylon-2.Nylon-6 3
Q21. (a) Give the
IUPAC name of :
[Co(cl)3 (H20)3]2+
(b)Drow the splitting diagrame for octahedral complex and define what is
CFSE. 3
Q22. Explain the
following observations:
(a) What is role of NaCN in froath flotation process.?
(b) Difference beetwen lyophilic and liophobic substances.
(c) From the CO and C ,which is best reduction agent for general oxide
at 500 k temperature? 3
Q23. Rajesh went to textile shop with his mother
to purchase dress material for his school uniform. Rajesh wanted pure cotton
fabric which looked bright, while mother insisted on blended fabric with 67%
terylene.
a) In your opinion, who is right?
b) What are the monomers of
Terylene?
c) What are the values involved in
the selection of the fabric?
3
Q 24. The
decomposition of N2 O5 (g) is a first order reaction with
a rate constant of 5 x 10-4 sec-1 at
45o C. i.e.
2N2 O5
(g)---à
4NO2 (g) + O2 (g).
If initial concentration of N2 O5 is 0.25M,
calculate its concentration after 2 min. Also calculate half
life for decomposition of N2 O5 (g).
(b) For an elementary reaction the rate of appearance of C at time ‘t’
is 1.3 x 10-4 mol -1 s-1 .
Calculate at this time
(i) Rate of the reaction. (ii) Rate of disappearance of A. 5
OR
(a) An organic compound ‘A’ with molecular formula C5 H8
O2 is reduced to n-pentane on treatment
with Zn-Hg/ HCI. ‘A’ forms a dioxime with hydroxylamine and gives a
positive lodoform test and Tollen’s test. Identify the compound A and deduce
its structure.
(b) Write the chemical equations for the following conversions:
(i) Methyl amine into Ethyl amine
(ii) Benzene into Benzyl alcohol.
(iii) Acetone to tert-Butyle alcohol
Q25. (a)
Which of the following two compounds would react faster by SN1
1 – bromobutane
or 2 – bromobutane and 2-Methyl 2- bromo butane.?
(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 give different
compound.?
(d) Transition metals have high enthalpies of atomization.
(e) Among the lanthanoids, Ce(III) is easily oxidised to Ce(IV).
isocyanide as main product. Give reason.
OR
(a) How activation energy affected by catalyst and
temerature.?
(b) Account for the following:- Ferric hydroxide sol is
positively charge sol.?
(b) Give chemical equation which occur
(a) K2 Cr2 O7
+ H 2SO 4 + C2H5OH-----------à
(b)
XeF 4 + O2 F2 ----------à
(c) 2H3
PO3 ----------^------à
5
Q 26. Give reasons
for the following:
(a) ClF3 is known but Fcl3 does not known. ?
(b) Sulhur is solid but Oxygen is gas.?
(c) ICl is more reactive than I2 ?
(d)Drow the structure of N 205.
(e)Only Xe from inert gases make compound with O and F atom. While other
gases does not. 5
OR
An element ‘A’
exists as a yellow solid in standard state. It forms a volatile hydride ‘B’
which is a foul smelling gas and is extensively used in qualitative analysis of
salts. When treated with oxygen, ‘B’ forms an oxide ‘C’ which is a colourless,
pungent smelling gas. This gas when passed through acidified KMnO4 solution,
decolourises it. ‘C’ gets oxidized to another oxide ‘D’ in the presence of a
heterogeneous catalyst. Identify A,B,C,D, and also give the chemical equation
of reaction of ‘C’ with acidified KMnO4 solution and for conversion of ‘C’ to
‘D’.
Comments
Post a Comment