CHEMISTRY (55)    TIME - 3Hrs        Max Marks - 70

Notes : 1) All questions are compulsory

2) Answers to the uestions of Section-1 and Section-11 should be written in the same answer book.

3) Draw neat, labelled diagrams and write balanced chemical equations wherever necessary

4) Figures to the right indicate full mards. 

5) Use of lofarithmic table is allowed. 

6) Answer to every new question must be started on a new page.

Section - 1

Q.1. Select and write the most appropriate answer from the given alternatives for each sub-question :

i) The process in which the value of ∆U= 0 is -------------

a) Adiabatic           b) Isothermal   c) Isobaric         d) Isochoric

ii) An ionic crystal lattice has r²/rˉ radius ratio of 0.320, its co-ordination number is - ----

a) 3       b) 4       c) 6        d) 8

iii) In hydrogen-oxygen fuel cell the carbon rods are immersed in hot aqueous solution of -------

a) KCL      b)KOH        c)H₂SO₄          d) NH₄CL

iv) The chemical formula of willemite is -----------

a) ZnS         b) ZnCO₃       c) ZnO          d) Zn₂SiO₄

v) The osidation state of nitrogen in dinitrogen trioside is----------

a) +1     b) +2        c)+3         d) +4

vi) Which of the following 0.1M aqueous solutions will wxert highest osmotic pressure  ?

a) AL₂(SO₄)₃           b) Na₂SO₄         c) MgCl₂             d) KCl

vii) The half-life period of zero order reaction A → Product is given by ---------

a)[A]₀/k                  b) 0.693/k         c) [A]₀/2k         d) 2[A]₀/k

Q.2 Answer any SIX of the following :

i) Derive the relation between elevation of boiling point and molar mass of solute.

ii) State third law of thermodynamics.  Give 'two' uses.

iii) Draw a neat and labelles diagram of leas storage battery.

iv) Ionic soliks are hard and brittle.  Explain.

v) A certain reaction occurs in the following steps-    Cl 

 

vi) Define :  a) Semipermeable membrane       b) Reference electrode

vii) What is the action of chlorine on :   a) CS₂        b) Excess NH₃

viii) Write the chemical equations involved in van Arkel method for refining zirconium metal.

Q.3 Answer any THREE of the following:

i) Write balanced chemical equations for the following :

a)Phosphorus reacts with magnesium. 

b) Flowers of sulphur boiled with calciun hydrodxide.

c) Action of ozone on hydrogen peroxide. 

ii) The density of iron crystal is 8.54 gram cm ˉᶾ. If the edge length of nit cell is 2.8 A° and atomic mass is 56 gram molˉ¹, find the numver of atoms in the unit cell.  (Given : Avogadro's number = 6.022 х 10²³, 1A° = 1х10ˉ⁸cm

iii) How many faradays of electricity are requered to produce 13 gram of aluminium from aluminium chloride solution  ?   

(Given : Molar mass of Al = 27.0 gram molˉ¹)

iv) Calculate the internal energy at 298K for the formation of one mole of ammonia, if the enthalpy change at constant pressure is -42.0 kJ molˉ¹

Q.4 i) Define : a) Enthalpy of atomization       b) Enthalpy of vaporization

ii) Draw the structure of IF₇.  Write its geomerty and the type of hyvridization.

iii) a) State Henry's law.

b) 22.22 gram of urea was dissolved in 300 grams of water.  Calculate the number of moles of urea and molality of the solution.   

(Given : Molar mass of urea= 60 gram molˉ¹ )

OR 

i) What is the action of carbon on the following metal oxides :      a) Fe₂O₃ in blast furnace b) ZnO in vertical retort furnace

ii) Write the molecular and structural formulae of : a) Thiosulphuric acid  b) Dithionous acid

iii) The reaction A+B→ products is first order in each of the reactants.

a) How does the rate of reaction change if the concentration of A is increased by factor 3  ? 

b) What is the change in the rate of reaction if the concentration of A is halved and concentration of B is doubled ?

SECTION - II

Q.5. Select and write the most approopriate answer from the given alternatives for each sub-question  :

i) A polymer used in paints is - 

a) Nomex          b) Thiokol       c) Saran        d) Glyptal

ii) The number of primary and secondary hydroxyl groups in robose are -

a) 1,3        b)2,3        c) 3, 1          d) 3, 2

iii) The ligand diethylene triamine is-

a) monodentate       b) bidentate    c) tridentate        d) tetradentate

iv) Propene on oxedation with diborane in presence of alkaline hydrogen peroxide gives -

a) propan-l-ol     b) propane -2-ol    c) allyl alcohol  d) propane-1-2-ol

v) Beayer's reagent is -

a) acidified potassium dichromate 

b)alkaline potassium dichromate

c) alkaline potassium permanganate

d) acidified potassium permanganate

vi) Identify 'A' in the following reaction- A+2Na Dry ether 2,2,5,5-Tetramethylhexane + 2 NaBr.

a) 2-Bromo-2-methylbutane b)1-Bromo-2,2-dimethylpropane       c) 1- Bromo-3-methylbutane    d) 1-Bromo-2-methylpropane

vii) An antifertility drug is -

a) Novestrol    b) Histamine    c) Veranal      d) Equanil

Q.6. Answer any SIX of the followin :

i) Write balanced chemical equations for the conversion of CrO₄²ˉ to Cr₂O₇²ˉ in acidic medium and  Cr₂O₇²ˉ to CrO₄²ˉ in basic medium.

ii) Explain the geometry of [ Co (NH₃)₆]ᶾ⁺ on the basis of hyvridisation.

(Z of Co = 27)

iii) Why ethanol has higher boiling point than ethane   ?

iv) Write only reactions for the preparation of benzophenone from cenzonitrile/

v) What is the action of p-tolunesulphonylchloride on ethylamine and diethylamine  ?

vi) What are amino acids  ?  Write the correct reaction for formation of peptide bond between amino acids.

vii) Define : 1) Antiseptics         2) Antioxidants

viii) Explain only reaction mechanism for alkaline hydrolysis of tert-butylbromide.

Q.7. Answer any THREE of the following  :

i) Complete and rewrite the balanced chemical equations-

a) Chlorobenzene NaCN+CuCN/ 473K,pressure ?

b) Isobutyraldehyde 50% KOH  ?

c) Buranone+ 2,4 dinitro-phenyl hydsrazine H⁺  ?

ii) Prepare carbolic acid from benzene sulphonic acid.  Write a chemical equation for the action of neutral ferric chloride on  phenol.

iii) Explain the preparation and uses of nylon-2-nylon-6.

iv) How glucose is prepared from cane sugar  ?  Write the formula of the complex copper (II) Hexacyano ferrate (II)

Q.8. What is lanthanide contraction  ?

Explain the cause of lanthanide contraction.

How are thylamice and ethyl methyl amine distinguished by using nitrous acid  ?

OR 

What is the action of the following reagents on ethanoic acid  ? 

A) LiAlH₄/H₃O⁺   

B) PCL₃, heat 

C) P₂O₅,heat 

Identify 'A' and 'B' in the following reaction and rewrite the complete reaction : 

CH₃ - CH₂ - Br + AgCN  → A   Na/C₂H₅OH → B

Explain Hoffmann bromamide degradation reaction.