Federal Public Service Commission (FPSC)
Competitive Examination for Recruitment to BPS-17 Posts under the Federal Government
Time Allowed: 3 Hours
MAXIMUM MARKS: 100 Marks
CHEMISTRY, PAPER-I
PART-II
Attempt FIVE questions in all, Including Questions No.1 which is COMPULSORY, All questions carry EQUAL marks.
Q. No. 2. (a) What is the Schrödinger wave equation? Discuss its importance in quantum chemistry. (06)
(b) Solve the Schrödinger wave equation for a particle in a three-dimensional box and find the expression for the energy and wave function. (08)
(c) What is a well-behaved function? What are the requirements of a physically acceptable wave function? (06)
Q. No. 3. (a) What is Gibbs free energy? Discuss its significance in chemistry. (06)
(b) Give a brief account of transition state theory indicating its advantages over collision theory. (08)
(c) Explain the 3rd law of thermodynamics. How is this law useful to determine the absolute value of entropy? (06)
Q. No. 4. (a) Define and explain the Langmuir adsorption isotherm. What are its limitations? (08)
(b) What is acid-base catalysis? Discuss its significance in chemistry. (06)
(c) What is the Phase rule? Discuss its application in a one-component system. (06)
Q. No. 5. (a) What are the solubility product and common ion effect? Discuss their significance in chemical analysis. (08)
(b) Valence shell electron pair repulsion theory can be used to predict the shapes of molecules. Using this theory explain the shapes acquired by BF₃ and IF₅. (07)
(c) Explain why the HSH bond angle in H₂S is slightly less than the tetrahedral angle 109.5°. (05)
Q. No. 6. (a) Describe the main features of crystal field theory. How does this theory explain the colour of coordination complexes? (10)
(b) Write the electronic configuration for each of the following: Ni²⁺, Cu, Mn²⁺, Cr³⁺. (04)
(c) What is the Jahn-Teller theorem? Explain its significance in coordination chemistry. (06)
Q. No. 7. (a) What are lanthanides? How are these extracted from their ores? (10)
(b) What is the decay law? How are half-life and decay constant related to each other? (05)
CHEMISTRY, PAPER-II
Attempt FIVE questions in all, Including Questions No.1 which is COMPULSORY, All questions carry EQUAL marks.
PART-II
Q. No. 2. Write briefly on the following terms: (2 x 10 = 20)
(i) Hyper-conjugation
(ii) Aromaticity
(iii) Grignard’s reagent
(iv) S_N1 reaction
(v) Molecular chirality
(vi) Monosaccharides
(vii) Chemical shift
(viii) Glycolysis
(ix) Detergents
(x) Friedel-Crafts alkylation
Q. No. 3. (a) How would you synthesize each of the following molecules from an alkene of appropriate structure (structure of your choice): (2 x 4 = 08)
(i) (CH₃)₂CH-CH(OH)-CH₃
(ii) (CH₃)₂CHO-CH₂-CH₂Cl
(iii) CH₃-CH₂-CH₂-CH(Br)-CH(Br)-CH₂-CH₂-CH₃
(iv) 2-Methylcyclohexanone [Cyclohexanone ring with a -CH₃ group at C2]
(b) Write the expected major product of the reaction of propyne with each of the following reagents: (1 x 6 = 06)
(i) Cu₂Cl₂, O₂, pyridine
(ii) Na, ND₃
(iii) [(CH₃)₂CHCH₂CH₂]₂BD, then CH₃CO₂H
(iv) H₂O, HgSO₄, H₂SO₄
(v) Di-isoamylborane, then NaOH, H₂O₂
(vi) Di-isoamylborane, then CH₃CO₂D
(c) Starting with benzene, design reasonable syntheses of each of the following compounds: (2 x 3 = 06)
(i) Benzyl alcohol
(ii) Benzaldehyde
(iii) 1-Phenylpropan-2-amine
Q. No. 4. (a) Consider the reaction of bromocyclohexane with each of the four reagents below, and answer the questions below. Also write down the reaction mechanism in each case: (07)
Reagents: H₂O, OH⁻, CH₃COOH, CH₃COO⁻
(i) What is the most important type of reaction mechanism in each case?
(ii) Which reagent gives the most elimination product?
(iii) Which reagent is most useful in synthesizing the alcohol?
(b) Evaluate each of the possible alcohol syntheses below as being good (the desired alcohol is the major or only product) or not so good (the desired alcohol is a minor product, or worthless): (05)
(i) CH₃CH₂Cl + H₂O/OH⁻, Δ CH₃CH₂OH
(ii) (CH₃)₂CH-CN + H₂O/OH⁻, Δ (CH₃)₂CH-OH
(iii) CH₃-O-CH₃ + H₂O/OH⁻, Δ CH₃OH
(iv) p-Toluenesulfonate cyclohexyl ester + H₂O/OH⁻, Δ Cyclohexanol
(v) Iodocyclohexane + CH₃OH Methoxycyclohexane / Cyclohexanol
(c) Write the major product(s) of each of the following reactions. It is implied that aqueous work-up has taken place in all those cases that require it to obtain the organic product: (08)
(i) CH₃CHO + 1. LiAlD₄ / 2. H⁺, H₂O
(ii) 2-Bromocyclohexan-1-one + LiAlH₄, (CH₃CH₂)₂O
(iii) (CH₃)₂CHBr + Mg, (CH₃CH₂)₂O Grignard reagent + [Carbonyl Compound]
(iv) 2,2-Dimethyl-1,3-dioxolane + H₂, Pt
Q. No. 5. (b) Draw the structures of the following molecules: (10)
(i) 5-(2,2-Dimethylpropyl)nonane
(ii) 2,3-Dimethylhept-3-ene
(iii) 1-Chloro-1-methoxy-2-methylbut-1-ene
(iv) 6-Chloro-2-nitrooct-1-en-3-yne
(v) 8-Chloro-7-methoxy-5-methyl-4-nitroundec-5-ene
(vi) 4-(2-Ethylbutyl)decane
(vii) 5-Ethyl-4,6-dimethylhept-4-en-2-yne
(viii) 5,5-Dichloro-3-methylhepta-3,6-dien-1-yne
(ix) 6-bromo-5-chloro-9-nitropentadecane
(x) 6-chloroocta-1,3-diyne
(c) (i) The structure (I) given below has a significant dipole moment. Which end of the molecule would you expect to owe a positive charge, and which tends to be negative? (02)
[Structure I: Substituted Fulvene / Azulene polar ring system]
(ii) The structure (II) given below is a component of certain oral contraceptives. Locate in this structure an example of each of the following bonds or atoms: (03)
A highly polarized covalent bond
sp-hybrid carbon atoms
A nearly unpolarized covalent bond
Q. No. 6. (a) The two isomers of carvone are given below. Which is R and which is S? (02)
(+)-Carvone, (-)-Carvone
(b) The structure of the compound given below is a sugar called (-)-arabinose. Its specific rotation is -105°. (04)
(i) Draw enantiomer(s) of (-)-arabinose
(ii) Draw diastereomer(s) of (-)-arabinose
(iii) Does (-)-arabinose have any optically inactive diastereomers? If it does, draw one.
(c) Assign E, Z designation to the following structures: (03)
(i) Substituted Alkene Structure 1
(ii) Substituted Oxime / Diimide Structure 2
(iii) Substituted Alkene Structure 3
(iv) Substituted Alkene Structure 4
(v) Substituted Alkene Structure 5
(vi) Substituted Imine Structure 6
(d) Draw the structures of the product(s) described for each reaction. Specify all aspects of the stereochemistry: (03)
(i) Stereospecific anti addition of bromine to cis- and trans-cinnamic acid.
(ii) Methanolysis of S-3-bromooctane with 6% racemization.
(iii) Stereospecific syn thermal elimination of acetic acid from 1R,2S-diphenylpropyl acetate.
(iv) Stereoselective epoxidation of bicyclo[2.2.1]hept-2-ene proceeding 94% from the exo face.
Q. No. 7. Write a brief account on the following: (5 x 4 = 20)
(a) Biological importance of starch
(b) Classification of Amino acids
(c) Primary structure of Proteins
(d) Glycogenesis
Q. No. 8. (a) Differentiate the following using IR Spectroscopy: (05)
(i) Primary, Secondary, and Tertiary Amines
(ii) Carboxylic acids, Ketones, and Esters
(iii) Alkane, Alkene, and Alkyne C-H/C-C linkages
(iv) Saturated open-chain hydrocarbons
(b) What type of electronic transitions are possible in the following compounds? (04)
(i) Butadiene (ii) Diethyl ether (iii) Acetaldehyde (iv) Trimethylamine
(c) How will you distinguish the following compounds using a UV/Visible spectrophotometer? (04)
(i) Nitrobenzene derivatives (ii) Cis and Trans isomers
(iii) Cyclohexanone vs conjugated enones (iv) Conjugated vs non-conjugated dienes
(d) Give the expected chemical shift values for each proton in the following compounds: (04)
(i) Tetramethylethylene
(ii) trans-2-Butene
(iii) 1-Chloroprop-1-ene
(iv) 1-Bromo-2,2-dimethylpropane
(v) Substituted aromatic/alkyl proton configurations
(e) The mass spectrum of a compound shows the following peaks: m/e = 120, relative intensity = 20% (M⁺ peak); m/e = 105, relative intensity = 80%; m/e = 77, relative intensity = 96%; m/e = 43, relative intensity = 35%. Assign the structure which would be expected. (03)
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