CHEMESTRY(HONOURS)PAPER-IV-2005
Group-A
1. State and explain Kohlrausch's Law of independent migration of ions. How is the law
helpful in determining the equivalent conductance of a week electrolyte at infinite
dilution ?
Calculate the equivalent conductances at infinite dilution of sodium- potassium oxalate
solution. The ionic conductances of C2𝑜42− , 𝑘 + and N𝑎+ at infinite dilution are 148, 50
and 73.5 oh𝑚−1 c𝑚2 𝑚𝑜𝑙 −1 respectively.
2.
(a) Explain the terms :
(i) Concentration cell with and without transport
(ii) Liquid junction potential
(b) Given the data
.
■
MnO4+ 8H+ + 5e→Mn2+ + 4H2O; £°= 1.51V
Mn3+ + e-→Mn2+;E°=1.5l V
Calculate the standard potential for
Mn𝑜4− + 8H+ + 4e- → Mn3+ +4 𝐻2 0
3. Derive Langmuir adsorption isotherm. Explain, how the variation of adsorption , is
accounted for (a) at lower pressure, (b) at higher pressure and (c) in the intermediate
range of pressure.
Group-B
4.
(a) Write the formula and IUPAC name of a three carbon containing saturated (i)
rnonohydric alcohol, (ii) dihydric alcohol and (ii) trihydric alcohol.
(b) Starting from compounds of your choice, outline two methods for tht synthesis of
each of them.
(c) Treating 3-methyl-2-butanol with HBr yields 2-bromo-2methyl butt the sole
product. Outline the mechanism.
5.
(a) What are phenols ? Compare their acidic properties with those of alc< (b) Identify
the products and the names of the reactions :
(b) Identify the products and the names of the reactions:
6.
(c) Outline the mecftanism of any two of the above given reactions.
(a) What are epoxides ? How are they synthesised ?
(b) Give the mechanism of (i) acid catalysed ring opening and (ii) ba e catalysed ring
opening of epoxides.
(c) Treating 2,2-dimethyl oxirane with NaOCH3 in methanol gives primarily 1 ■
methoxy-2 methyl-2-propanoi. Explain.
(d) Acid catalysed hydrolysis of 1,2-epoxy-cyclopentane yields trans1-2 cyclopentane
diol. Explain, with mechanism. .
I 7. Give the names of the reactions represented by the equations:
Discuss the mechanism of any three of the bove given reactions.
8. Write all the isomers of a compound with the molecular formula C3H are their IUPAC
names and is there any possibility of stereoisoi Explain.
Outline the synthesis of each of the isomers using either Gi phythalimide reaction or
reductive amination of aldehydes and ket<
9.
Write notes on any three of the following reactios :
(a) Diazotisation (b) Baeyer-Villiger oxidation (c) Cannizzaro
(d) HVZ-reaction
CHEMESTRY(HONOURS)PAPER-IV-2006
Group-A
1. (a) What is meant by transport number of ions ? Describe Hittorf's method
for the determination of transport number of silver ions.
(b) A.solution of silver nitrate containing 12.14 gm of snver in 50 ml of solution was
electrolysed between platinum electrode. After electrolysis 50 ml of the anode
solution was found to contain 11.55 gm of silver while 1 .25 gm metallic silver was
deposited on the cathode. Calculate tin transport number of A𝑔+ and N𝑜3− ions
2. (a) Define PH. Describe with the help of a diagram the working of quinhydrone
electrode and show how it can be used to determine the PH of the solution
(b) Find the PH of a solution placed in a hydroquinone half cell which was
coupled with standard calomel electrode. The e.m.f. of the combined cell
was determined to be 0.123 V at 25°C. Ecalomel = O.2415 V, EOa=O.6996V
3.
Write short notes on following:
(a) Absorption and Adsorption (b) Freundlich Adsorption Isotherm (c) Langmuir
Adsorption Isotherm
Group-B
4.
(a) How Propene can be converted into Glycerol ?
(b) How glycerol reacts with the following compounds ?
(a) Oxalic Acid (b) KHS04 (c) PC𝐿5 (d)Acetylchloride.
5.
Explain the following:
J
(a) Why formic acid is more stronger than acetic acid ? (b) Carboxylic acid have high boiling
point than alcohols, (c) Hell-Volhard-Zelinsky reaction (d) Decarboxylation of Carboxylic
acid (e) Action of heat on dicarboxylic acid.
6. Write the mechanism of the following reactions:
. (a) Perkin's reaction (b) Aldol Condensation (c) Wittig reaction (d)
Knoevenagee reaction
7. (a) How you can separate mixture of Primary Amine, Secondary Amine and Tertiary
Amine?
(b) Haw can you prepare Phenol, Choloro Benzene, Bromo Benzene and lodo Benzene from
Benzene Diazonium Chloride ?
8. Write the mechanism of the following reactions:
(a) Reimer-Tiemann reaction (b) Fries Rearrangement (c) Gattermann Synthesis (d) KolbeSchmitt Reaction
9. (a) Explain the principle of uv spectroscopy. Exaplain why a uv spectrum
consists of bands and not of peaks.
(b) the uv spectrum of acetone shows absorption maxima at 166,189,189 and 279nm. What
type of transition is responsible for each?
(c) Define the following terms:
(i) Bathocromic effect(ii) Hypochromic effect.
CHEMESTRY(HONOURS)PAPER-IV-2008
Group-A
1.
(
a) Define specific conductivity and equivalent conductance.
(b) State and explain Kohlrausch's law.
(c) State Arrhenius theory of electrolytic dissociation with its limitations.
2.
Write short notes on the following :
(a) Nernst equation and its applications
(b) Concentration cell with and without number
(c) pH and pK of a solution
3.
(a) Differentiate between absorption and adsorption.
(b)What is Langmuir’s adsorption isotherm? How does it vary at lower pressure and
high pressure.
4.
(a) What is Beer-Lambert law ?
5.
(b)Explain 1R spectroscopy and its application. State the fingerprint region in 1R
spectra.
Write 1UPAC names of the following :
(b) Explain the oxidation of glycerol.
(c) State and explain pinacol-pinacolone rearrangement with its mechanism.
6.
(a) Compare the acidic strength of phenol and ethanol showing the.
resonance stabilisation of phenoxide ion.
(b) Write the. mechanism of any two of the following:
(i) Fries rearrangement (ii) Claisen rearrangement (iii) Reimer-Tiemann
reaction
7.
(a) Explain the electronic structure.of ketonic group [>C=O].
(b) State and explain with mechanism any two of the following :
(i) Benzoin condensation (ii) Perkin condensation (iii) Canni//ain reaction
8. (a) Explain the acidity of carboxylic group
(b) Chloroacetic acid is stronger than acetic acid. Explain it.
(c) Give preparation, properties and uses of urea in brief.
9. (a) Write all the isomers of a compound with molecular formula 𝐶3 𝐻9 𝑁
What are their IUPAC names ? Is there any possibility of sterioisomerism ?
(b) Explain the following:
(i) Basicity of amines (ii) Hofmann bromamide reaction.