PUC-II Chemistry 2006
PART – A
Note: i)
Answer all the 10 questions.
ii) Questions have to be answered in one word or in one sentence each. Each question carries one mark.
10x1=10
1. Out of
carbon and zinc which is a stronger reducing agent ?
2. Why is Fe 3 + ion more stable than Fe 2 + ion ?
3. If the rate
of the reaction is independent of concentration of the reactant,
what is the order of the reaction ?
4. Which noble
gas is not adsorbed by charcoal ?
5. What is
hydronium ion ?
6. What is the
only factor on which the colligative property value depends ?
7. Between
potassium nitrate and aluminium nitrate which one is required in
minimum concentration to coagulate
arsenious sulphide sol ?
8. Which is
the organic product obtained when methyl magnesium iodide
reacts with formaldehyde followed by acid
hydrolysis ?
9. Name the
least stable cycloalkane.
10. How many
amino acid units are present in insulin ?
PART – B
Note: i)
Answer any ten questions.
ii)
Each question carries two marks.
10 X 2 = 20
11. Justify
that concentrated sulphuric acid is a good dehydrating agent with
example.
12. Calculate
the bond order in oxygen molecule.
13. The time
for half-life of a first order reaction is found to be 30 mins. What
is the rate constant of the reaction ?
14. Define
Faraday’s first law of electrolysis.
15. What is a
spontaneous reaction ? Explain with an example.
16. What is
Tyndall effect ? Explain.
17. Calculate
the number of particles present in the unit cell of BCC.
18.
Distinguish between inductive effect and electromeric effect.
19. Explain
the effect of the following substituents on the acidity of phenol :
i)
— CH 3 group
ii)
— NO 2 group.
20. How is
ethanamine prepared from ethane nitrile ?
21. What are
reducing and non-reducing sugars ? Give one example each.
22. What are
biological messengers ? Give an example.
PART – C
2x5=10
I. Answer any two of the following :
23. a) How are noble gases separated by
Dewar’s charcoal adsorption
method?
3
b)
With the help of the Ellingham’s diagram, explain why silver
oxide
can be thermodynamically decomposed at relatively lower
temperature.
2
24. a) Give 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. Give
reason.
2
25. a) Describe the manufacture of sodium
hydroxide using
Nelson’s
cell. 4
b)
Write the IUPAC name of [CO (NH3)4 Cl
2 Cl2]C1.
II. Answer any
three of
the following : 3 × 5 = 15
26. a) Discuss the molecular orbital
structure of benzene. 3
b)
Explain geometrical isomerism with an example. 2
27. a) What is S N 1 mechanism ? Explain it using hydrolysis t-butyl
bromide.
3
b)
Give any two uses of aniline. 2
28. a) Write the Howarth’s ring structure for â-D ( – ) fructopyranose. 2
b)
Define 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 following
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 ? 1
III. Answer
any three of
the following : 3
X 5
= 15
30. a) How are the molecular orbitals formed
by the linear combination
of
atomic orbitals ? 3
b)
Distinguish between ideal and non-ideal solutions. 2
31. a) Calculate the mass of potassium acetate
that should be
dissolved
in 500 cm 3 of 0·02 M acetic acid solution to prepare
a
buffer solution of pH 4·6.
Given
K a = 1·8 X 10-5.
3
b)
Define the following terms : 2
i) Protective colloid
ii) Gold number.
32. a) Discuss 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 ( Δ G° ) for a
reaction is
–
115 kJ at 27°C. Calculate the equilibrium constant ( K p ).
2
33. a) Derive an expression for the velocity
constant of a first order
reaction.
4
b)
Acetic acid very weakly dissociates in presence of hydrochloric
acid.
Give reason. 1
34. a) With diagram, explain the construction
and working of standard
hydrogen
electrode. Give two limitations. 4
b)
Define radius ratio in ionic crystals. 1
PART – D
IV. Answer any
one of
the following : 1X10=10
35. a) Explain the chemical reactions that
occur during the extraction
of
iron from haematite by smelting in a blast furnace. 3
b)
What is angle strain ? Calculate the angle strain in cyclobutane. 3
c)
What is a pseudounimolecular reaction ? Give an example. 2
d)
Calculate the e.m.f. of the cell prepared by combining
Zn
| 1 M ZnSO 4 and Cu | 1 M CuSO 4 at 298 K.
Given
E 0
Zn = – 0·76 V and E 0
Cu = + 0·34 V . 2
36. a) On the basis of Valence bond theory,
explain hybridisation,
geometrical
shape and magnetic property in Cuprammonium
sulphate.
3
b) i) Explain Perkin’s reaction with an
example. 2
ii) How is acetic acid prepared from
ethanol ? 1
c)
Calculate the osmotic pressure of 10% solution of glucose
at 27°C. Given R = 8·314 JK –
1 mol – 1 . 2
d)
Give any two demerits of Arrhenius theory of ionisation. 2
V. Answer any two of the following : 2
X 5
= 10
37. a) Explain the preparation of m-dinitrobenzene from nitrobenzene. 3
b)
Describe Acrolein test. 2
38. Describe an experiment to show the effect
of temperature on the rate
of
the reaction between potassium persulphate and potassium
iodide.
5
39. Describe the experiment to determine the
mass of Mohr’s salt
crystals
in one dm 3 solution by using standard potassium
dichromate solution. Give the equation for
the reaction involved. 5
