Pre University Board 2006 P.U.C Physics, Chemistry, Maths

21. elaborate reducing and non-reducing sugars ? provide 1 example every.
22. elaborate biological messengers ? provide an example.
PART – C
I. ans any 2 of the subsequent : two × five = 10
23. a) How are noble gases separated by Dewar’s charcoal adsorption
method ? 3
b) With the help of the Ellingham’s diagram, discuss why silver
oxide can be thermodynamically decomposed at relatively lower
temperature. 2
24. a) provide the postulates of Werner’s theory of coordination
compounds. 3
b) Copper (I) compounds are white and diamagnetic whereas
Copper (II) compounds are coloured and paramagnetic. provide
reason. 2
25. a) define the manufacture of sodium hydroxide using
Nelson’s cell. 4
b) Write the IUPAC name of ?
?
? ?
CO ( NH ) three four Cl two Cl. 1
II. ans any 3 of the subsequent : three × five = 15
26. a) explain the molecular orbital structure of benzene. 3
b) discuss geometrical isomerism with an example. 2
27. a) What is S N one mechanism ? discuss it using hydrolysis t-butyl
bromide. 3
b) provide any 2 uses of aniline. 2
28. a) Write the Howarth’s ring structure for ß-D ( – ) fructopyranose.
2
b) describe the term ‘iodine value of an oil’. Mention its significance.
2
c) What is isoelectric point of amino acids ? 1
29. a) Write the equations for the subsequent reactions : 4
i) Mixture of calcium formate and calcium benzoate is dry
distilled
ii) Acetaldehyde is treated with hydroxyl amine
iii) Acetone is treated with hydrogen cyanide
iv) Phenol is heated with a mixture of conc. nitric acid and
conc. sulphuric acid.
b) How do you convert Methane to Ethane ?


III. ans any 3 of the subsequent : three × five = 15
30. a) How are the molecular orbitals formed by the linear combination
of atomic orbitals ? 3
b) Distinguish ranging from ideal and non-ideal solutions. 2
31. a) compute the mass of potassium acetate that should be
dissolved in 500 cm three of 0·02 M acetic acid solution to prepare
a buffer solution of pH 4·6.
provided K a = 1·8 × 10 – five . 3
b) describe the subsequent terms : 2
i) Protective colloid
ii) Gold number.
32. a) explain the application of the principles of solubility product
with respect to the analysis of II and IV group basic radicals. 3
b) The standard free energy change ( ? G° ) for a reaction is
– 115 kJ at 27°C. compute the equilibrium constant ( K p ). 2
33. a) Derive an expression for the velocity constant of a 1st order
reaction. 4
b) Acetic acid very weakly dissociates in presence of hydrochloric
acid. provide cause. 1
34. a) With diagram, discuss the construction and working of standard
hydrogen electrode. provide 2 limitations. 4
b) describe radius ratio in ionic crystals. 1

PART – D
D 1
IV. ans any 1 of the subsequent : one × 10 = 10
35. a) discuss the chemical reactions that occur during the extraction
of iron from haematite by smelting in a blast furnace. 3
b) What is angle strain ? compute the angle strain in cyclobutane.
3
c) What is a pseudounimolecular reaction ? provide an example. 2
d) compute the e.m.f. of the cell prepared by combining
Zn | one M ZnSO four and Cu | one M CuSO four at 298 K.
provided E 0
Zn = – 0·76 V and E 0
Cu = + 0·34 V . 2
36. a) On the basis of Valence bond theory, discuss hybridisation,
geometrical shape and magnetic property in Cuprammonium
sulphate. 3
b) i) discuss Perkin’s reaction with an example. 2
ii) How is acetic acid prepared from ethanol ? 1
c) compute the osmotic pressure of 10% solution of glucose
at 27°C. provided R = 8·314 JK – one mol – one . 2
d) provide any 2 demerits of Arrhenius theory of ionisation. 2
15 Code No. 34-NS
36 [ Turn over
D 2
V. ans any 2 of the subsequent : two × five = 10
37. a) discuss the preparation of m-dinitrobenzene from nitrobenzene.
3
b) define Acrolein test. 2
38. define an experiment to show the effect of temperature on the rate
of the reaction ranging from potassium persulphate and potassium
iodide. 5
39. define the experiment to determine the mass of Mohr’s salt
crystals in 1 dm three solution by using standard potassium
dichromate solution. provide the formula for the reaction involved. 5

Earning:   Approval pending.