Download "Physical Chemistry B-Chemistry" Question Paper PDF of B.Sc. 4th Semester Previous Years Paper for Students.

B.Sc. (General) 4th Semester
Chemistry
Same for B.Sc. Microbial & Food Technology)
Paper-XV: Physical Chemistry-B 

Time Allowed: Three Hours]

Maximum Marks: 22 

Note: (1) Attempt five questions in all, selecting at least one question from each Section. Section E is compulsory. (2) Use of log tables and simple calculators is allowed.

SECTION-A

1. (a) State and explain 'Nernst Distributions Law'. Prove that the law does not undergo modification if the solute undergoes chemical combination with one of the solvents except that the numerical value of partition coeffiecient changes. 

(b) What do you understand by 'Critical Solution Temperature' (CST) ? Explain a system which has both upper CST as well as lower CST.

2 (a) Define 'Gibb's Phase Rule'. Derive it thermodynamically. 

(b) What do you understand by congruent and incongruent melting points? What is the number of components and the degree of freedom at congruent melting point of a system, consisting of two components?

SECTION-B

3. (a) Define 'Transport Number'. Describe briefly the principle underlying the determination of transport number by 'Hittorf's Method'.

(b) Calculate the concentration of hydronium ions in an aqueous solution of acetic acid in which 0.05 moles of acetic acid are dissolved in 250 ml of solution. Given that ka value for acetic acid is 1.8x10-5.

4. (a) Explain two interionic effects :

(i) Relaxation Effect

(ii) Electrophoretic Effect.

(b) The transport numbers of Ag+ ion and NO3, ion in an aqueous solution of AgNO3, are 0.466 and 0.534 respectively. The molar conductance at infinite dilution for this solution is 116.5 Scm2 gm eq-1 Calculate: 

(i) ionic conductances of Ag and NO3- ions

(ii) Absolute velocity of the two ions.

SECTION-C 

(a) Derive 'Nernst equation' for the following general reversible cell reaction. 

aA + bB ScC + dD

(b) Standard Electrode Potential of Copper Electrode at 298 K is +0.34 V, calculate the concentration limit beyond which the electrode will have a negative potential.

(b) Write down the 'Debye Huckel Onsagar' equation for strong electrolytes.

(c) Will the molar conductance at infinite dilution of a decinormal aqueous solution of a dibasic acid be the same as its equivalent conductance at infinite dilution or different?

(d) What do you understand by the temperature coefficient of emf of a galvanic cell.

(e) How can the feasibility of a cell reaction be predicted from its cell potential.

(f) Give two conditions which are necessary for the validity of 'Distribution Law.

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Download "Chemistry - Organic Chemistry-B " Question Paper PDF of B.Sc. 4th Semester Previous Years Paper for Students.

B.Sc. (General) 4th Semester
Chemistry 
(Same for B.Sc. Microbial and Food Technology)
Paper: Organic Chemistry-B 

Time Allowed: Three Hours 

Maximum Marks: 22

Note: - Attempt five questions in all, selecting one question from each Unit. Unit-V is compulsory.

UNIT-I 

(a) Write IUPAC names of the following: 

(i) COOH

COOH 

(ii) CH3-CH-CH2-COOH

C6H5

(b) Why carboxylate ion is more stable than carboxylic acid? Discuss.

(a) Convert:

    (i) Acrolein into Acrylic acid 

    (ii) Acrylic acid into 2,3-dibromoprepanoic acid.

UNIT-V 

(i) Flouroacetic acid is a stronger acid than chloroacetic acid. 

(ii) Why C-O bond lengths in carboxylic acids are equal? 

(iii) Write the order of basic character of methylamine in the aqueous phase.

 (iv) Formula of Hinsberg reagent. 

(v) Write the equation to show that Cut2 gives blue colour with ethyl amine. 

(vi) During nitration of arenes, what is electrophile in the nitrating mixture (Conc. HNO, +H,50.)?

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Download "Organic Chemistry-A Paper-2" Previous Years Question Paper of B.Sc. (General) for 1st Semester.

B.Sc. (General) 1st Semester

Chemistry(Same for B.Sc. Microbial & Food Tech.)

Paper-II: Organic Chemistry-A

Time Allowed: Three Hours] [Maximum Marks: 22 

Note:- Attempt five questions in all selecting one from each Unit. Q.No. 9 is compulsory.

UNIT-I 

1. (a) Define resonance effect. Explain why allyl and benzyl halides are more reactive than primary alkyl halides towards nucleophilic substitution reaction? 

(b) What conditions are to be satisfied for a compound to be aromatic? State which of the following are aromatic and why?

 

2. (a) What are substitution reactions ? Give one example each for nucleophilic, electrophilic, and free radical reactions. 

(b) Give details for the various methods available for determining the reaction mechanism of a reaction. 2,2

    

UNIT-II 

3. (a) Give the details for the preparation of alkanes via decarboxylation of carboxylic acids. 

(b) Write a note on nitration of alkanes.  2,2 

4. (a) Write a note on [2 + 2] cycloaddition reactions for the preparation of cycloalkanes. 

(b) Discuss the salient features of Baeyer's strain theory. Calculate the angle strain in cyclobutane.  2,2

UNIT-III 

5. (a) What is metamerism ? Give a suitable example.

(b) Define the term, specific rotation. 

(c) Write a note on the inversion, retention of configuration, and racemization. 1,1,2 

6. (a) Giving suitable examples, differentiate between chiral centers and chiral molecules. 

(b) Draw the various possible stereoisomers for 2, 3-dichloro pentane. 

(c) Assign R or S configuration to the different chiral centers in the following compounds, showing the proper priority according to the CIP rule : 

 

UNIT-IV 

7. (a) With the help of the Newmann projection formula, explain why the chair form of methylcyclohexane is more stable as compared to the boat form? 

(b) What is the necessary and sufficient condition for geometrical isomerism in oximes?    2,2

8. (a) Write a detailed note on the determination of the configuration of geometrical isomers on the basis of their physical properties. 

(b) Assign E or Z nomenclature to the following compounds, showing the proper priority according to the CIP rule :

 

COMPULSORY QUESTION 

(a) Differentiate between localized and de-localized bonds. 

(b) What are nitrenes? Differentiate between singlet and triplet nitrenes. 

(c) Give the IUPAC nomenclature for the following compounds :

(d) Draw the Sawhorse, Fischer, Newmann, and Flying-Wedge projection for lactic acid. 

(e) How does geometrical isomerism affect melting point and boiling points? 

(f) Discuss the various methods for the resolution of a racemic mixture. 1x6

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Download "Inorganic Chemistry-A Paper-1" Previous Years Question Paper of B.Sc. (General) for 1st Semester.

B.Sc. (General) 1st  Semester
Chemistry 
Paper-I: Inorganic Chemistry-A

Time Allowed: Three Hours) [Maximum Marks 

Note:- Attempt five questions in all selecting one from each Unit I-IV. Q. No. 1 is compulsory. 

1. (a) What is Heisenberg's uncertainty principle?

(b) Which has a smaller size Cl or Cl-? Why? 

(c) How is XeF, prepared? 

(d) Why are alkali metals soft and have low melting points? 

(e) What is resonance? 

(f) Which of the following combinations give it molecular orbitals in the LCAO method (considering Z-axis to be the molecular axis) :

(i) 2s + 2s (ii) 2px + 2px (iii) 2p, - 2p, (iv) 2py + 2py     1x6

UNIT-I 

2. (a) Write Schrodinger wave equation for the Hydrogen atom. Name the three quantum numbers obtained from it and information conveyed by them. 2 

(b) What physical significance is attached to y and y? 2

3. (a) On the basis of the uncertainty principle, show that an electron cannot reside in the nucleus. 2

(b) Draw radial probability distribution curves for :

(1) n = 3,1 = 0 (ii) n = 2,1 = 1 2

UNIT-II 

4. (a) Electron affinity of Be and N are almost zero, while that of Ne is zero. Why? 1

(b) What are iso-electronic ions ? Arrange the following iso-electronic ions in the increasing order of their size and account for it: 0?, F., Na+, Mg? 3

5 (a) Calculate the electronegativity of chlorine atom using the following data : 

E - 104.2 kcal mol- E = 58.25 kcal molEl.cn = 103.28 kcal mol-' Electronegativity of H = 2.1 2

(b) Give reasons for the following: (i) Second ionization energy of an atom is always greater than the first ionization energy of an atom. 

(ii) Electron affinities of halogens are highest. 1,1

UNIT-III 

6. (a) Discuss the structure of XeF, How does it react with water ? 2

(b) Why do most of the noble gas compounds involve xenon, fluorine, and oxygen ? 2

7. Explain the following: 

(i) Lithium forms a normal oxide, sodium forms peroxide, and potassium, rubidium, and cesium form superoxide. 

(ii) Alkali metals dissolve in liquid ammonia to give a blue solution. 2,2 

UNIT-IV 

8. (a) Draw the Molecular Orbital diagram of BO and calculate its bond order. 2

(b) Calculate the dipole moment of HCl molecule if its bond length is 1.278 and % ionic character is 17%.2

9. (a) Discuss the shape and hybridization of PF, and SnCI2. 2

(b) Discuss the effect of change of electronegativity of central atom on bond angle.2

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Download "Chemistry" Question Paper of B.Sc. (Hons.) Biotechnology for B.Sc.1st Semester.

 B.Sc. (Hons.) Biotechnology

1st Semester 

BIOT-Sem-I-IV-T: Chemistry

Time allowed: 3 Hours Max. Marks: 67 

NOTE: Attempt five questions in all including Q No.-IX (Unit-III) which is compulsory and select two questions each from Unit I-II.

UNIT-I 

1. (a) Draw molecular energy level diagram of NO molecule. Tell its bond order and magnetic behavior. 

(b) What are Scater Rules? State properly calculate the effective nuclear charge for one of the 4s electron of zinc atom.

II. (a) Explain the term ionization energy. What are the different factors on which it depends? 

(b) Define the following terms: - 

(i) Chemical shift 

(ii) Shielding and deshielding of protons 

(iii) Zero point energy 

(iv) Stokes and anti stokes lines

III. (a) Differentiate ideal and non-ideal solutions. 

(b) Derive the relation between freezing point depression of solution and mole fraction of the dissolved solute. 

(c) Calculate osmotic pressure at O'C of a 5% solution of urea (mol. wt=60) (R=0.0821 lit-at/deg/mol).

IV. (a) Discuss in detail effect of catalyst on rate of reaction. 

(b) Differentiate order and molecularity. 

(c) Explain the effect of temperature on reaction rate in terms of Arrhenins equation.

UNIT-II 

(V) (a) State and explain Stark-Einstein law of photochemical equivalence. What do you mean by molar extinction coefficient? 

(b )Define and explain the terms Fluorescence and phosphorescence properly.

VI. (a) Explain the basic postulates of Werner's coordination theory.

(b) Write IUPAC names of the following: 

(i) K[Hg1] 

(ii) (Colen), CI, Br 

(iii) (CH(NH) 

(iv) LAH) 

(v) [Co(NH,),CI] 

( c )Explain with help of examples, geometrical isomerism in complexes having coordination number six. (5+5+3)

(VI )Differentiate inductive effect and electrometric effect. 

( b) Discuss and compare and sy reactions with help of mechanisms. 

( c )Write a note on structure, methods of preparation, and reactivity of singlet and triplet carbenes. (3+6+4)

VIII. (a )How will you account for the fact that acid chlorides are most reactive and acid amides are least reactive towards nucleophilic substitution reactions? Justify.

(b) Write and explain the mechanism of the following reactions: 

(i) Esterification 

(ii) HVZ reaction (7+6)

UNIT-III 

IX. Attempt the following: - 

(a) Define linkage isomerism in coordination complexes with one example. 

(b) Write the units of the rate constant for the first and second-order reaction. 

(c) What do you mean by activation energy? 

(d) Explain Allred and Rochow scale of electronegativity.

(e ) Tell three centred electron pair bond with example. 

( f) Explain briefly hyperconjugation.

( g) Briefly explain the terms transmittance and absorbance. 

(h) Which gas is commonly known as stranger gas?

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