Pre University Board 2009 P.U.C Physics, Chemistry, Maths & Biology " Chemistry " Code 34 - Question Paper
( Total No. of Printed Pages : 16
Total No. of Questions ; 39 ]
March, 2009
Instructions ; i) The question paper has four Parts.
il) Parts A, B, C and D are common to al! the candidates.
ill) Part A carries i() marks. Each question carries one mark.
Part B carries 20 marks. 1; question carries two marks.
Part C carries 40 marks, I'arh question carries Jive marks. In Part I> D t 10 ; and D 2 carries
wherever
PART - A Note: i) Answer a]] the ] 0 questions
ii) Qufcsiio:;-'- m o<- ./-ii n; f-nc iv'dp; iir in onv
10 y i - 10
1. Whai is the role of limestone ia the extract joa -s i: o:i trom haematite '
2 Hydrogen sulphide gas cannot be dried using vonc ii ., SO 4. Give reason.
3. Which one among Cu + 1 and Cit 2 * sails is coloured ?
4. What is the limitirrg value oi degree of dissociaiiun of an electrolyte at infinite dilution ?
5. Sea-water freezes below 273 K. Why "
6. Deiine electrophoresis.
( Turn over
Code No. 34 10
7. The coordination number of a crystal is 6. What is the geometry of the crystal ? . _
8. Name the gas liberated when bromoeUuUie is heated with alcoholic potash.
9. Phenol does riSt react with sodium bicarbonate. Why ?
10. Name the protein present in hair.
Note : i) Answer any ten questions.
ii) Each question carries livo marks. 10 x 2 = 20
i
11. Draw Ellingham diagram for the formation of oxides of aluminium and magnesium. Which one of these metals acts as better reducing agent above 1500C ?
12. How does potassium dichromate solution react with potassium
hydroxide ?
13. Calculate the EAN value of the central metal ion in ietramine copper (II) sulphate.
14. Sketch the shapes of bonding and antibonding molecular orbitals formed when two S orbitals undergo LCAO.
15. A first order reaction is 50% completed in 80 mln. Calculate the rate constant of the reaction.
16. Mention any two characteristics of an ideal solution.
11 Code No. 34
17. pH value of a sample of mango juice Is 4 54. Calculate the ( H + ).
18. Identify A, B, C and D in the following equation '
CH 3 - CH 2 - Cl ~ > CH 3 - CH 2 - OH CH 3 - COOH 1L> C
NaOH + CaO
-rtD .
heat
19. What is Wurtz-Fittig reaction ? Write the general equation.
20. Write the equations for the following reactions :
i) Diy distillation of calcium acetate
11) Reaction of phosphorous pentachloride with acetic acid.
21. Write the Haworth structure of a - D - maltose.
22. What happens when tristearin is heated with potassium hydroxide solution ? Give the equation.
I. Answer any two of the following questions : 2x5=10
23. a) Describe the manufacture of ammonia by Habers process. 3
b) Sketch the shapes of nickel tetracarbonyl. Which type of hybridisation is involved in the formation of this compound ? 2
\_>r24. a)- - How is a mixture of noble gases separated tjjr Dewar's charcoal
method ? 3
_______... ... b) Write the electronic configuration of lithium molecule. Comment
on its magnetic property with reason. 2
Code No. 34 12
25. a) State any three postulates of Werners theory of co-ordination compounds. 3
b) On the basis of ectron gas theory, explain bright lustre of metals. 2
II, Answer any three of the following questions : 3 x 5 = 15
26. a) What is mesomeric effect ? What type of mesomeric effect is
shown by - CHO group in benzaldehyde ? 2
b) Explain the mechanism of nitration of benzene. 3
I
27. a) How is phenol isolated from coal tar ? 3
b) What is a dipeptide ? How many peptide linkages are present in a tetrapeptide ? 2
28. a) What is optical activity ? Which one of the following compounds
shows optical isomerism ? 2
H OH
Br C Br Br C COOH
ch3 ch3
b) How is ethyl bromide converted into ethyl isocyanide ? Write ti
equation.
c) Give a chemical reaction to show that a molecule of gluco contains a carbonyl group.
13 Code No. 34
29. a) Calculate angle strain in cyclobutane. 2
b) Explain carbylamine reaction for a primary amine. Write general equation. 2
c) One mole of a given amine consumes two moles of methyl iodide for exhaustive methylation. What type of amine is this ? 1
III. Answer any three of the following questions : 3 x 5 = 15
.. 30. a) Derive an expression for rate constant of a first order reaction.
b) State Schultz-Hardy rule. 1
31. a) Explain buffer action in acidic buffer containing mixture of acetic acid and sodium acetate. 3
b) When the same amount of electricity passed through solutions of copper sulphate and hydrochloric acid, 64 mg of copper is deposited on the cathode in the first case. Calculate the volume of hydrogen obtained in the second case at S.T.P.
( Equivalent weight of Cu = 32 ). 2
, '32. a) Mention two limitations of standard hydrogen electrode. 2
b) Write Nemsf equation for single electrode potential. Explain any two terms in the equation. ..................2
c) Mention the dispersed phase and dispersion medium in a gel.
Code No. 34 14
33. a) Define entropy. What happens to entropy when a liquid
vaporises ? ~ 2
b) What Is Brownian movement ? How is it caused ? 2
c) Define unit cell. i
34. a) Calculate the change in free energy for the cell
H |
if E Ag = 0-8 V and E Mg =-2-37 V. 2
b) State any three postulates of Arrhenius theory of electrolytic
I
dissociation, 3
PART - D Di
IV. Answer any one of the following : 1x10=10
35. a) Describe Parkes process for the desllvcrisation of Argentiferrous lead. 3
b) Why are transition elements and their compounds good catalysts ? Explain. 2
c) For a reaction, the graph of rate of the reaction against molar concentration of the reactant is a straight line parallel to the concentration axis. What is the order of this reaction ? Give an example for such a reaction. 2
d) The value of standard free energy of formation of ammonia at 298 K Is - 16-6 kj mol' 1. Calculate the equilibrium constant
Kp for the reaction.
e) What is Iodine value ?
1
36. a) Give the mechanism of Cannizzaros reaction,
was passed through a solution containing compound in 61-2 g of diethyl ether and vent. The loss in mass of solution bulb was the solvent bulb was 0 035 g. Calculate the ne aromatic compound.
b) A current of dry air 5-4 g of an aromat then through the s< i O708 g and that in molecular weight of |t
|
( Given molecular w c) When NH 4 Cl and A1 3 + and Zn 2 + ions d) i) Write the IUPAO |
ight of diethyl ether = 74 ) 2 H 4 OH are added to a solution containing only A1 ( OH ) 3 precipitates. Give reason. name of |
H CH 2 COOH
CH 3
ii) Out of CH
<PH CH 2 COOH
nd
CH 3 CH 2
pH COOH
1 - -
which one has h gher pKa value ? 2
e) How many Lattice poijits are present in a unit cell of CsCl ? 1
( Turn over
V. Answer, any two of the following : 2 x 5 = 10
\jy?- aJ How is m-nitrobenzene prepared in the laboratory from nitrobenzene ? Write the equation. 3
b) Mention a general test for
i) Protein
ii) Carbohydrate. 2
38. Describe an experiment to show that aoid hydrolysis of methyl acetate follows first order kinetics. 5
.39. For the estimation of potassium permanganate ( KMnO 4 ) using standsu d ferrous ammonium sulphate
i) Write the chemical equation lor the reaction involved.
ii) Give the equivalent weight of potassium permanganate.
iii) Name the indicator used,
iv) What is the colour change at the end point ?
v) Write the equation for calculating mass / dm 3 of potassium permanganate in a given solution from its normality. 5
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| Earning: Approval pending. |
