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
Attempt FIVE questions in all, Including Questions No.8 which is COMPULSORY, All questions carry EQUAL marks.
1. (a) How is aluminum found in nature? (3)
(b) Write an account of the chemistry associated with the conversion of
Bauxite to aluminum. (8)
(c) What are the main impurities present in bauxite? How are they
eliminated? (4)
(d) It is now said that we are now living in the aluminum age. Discuss
the truth of this statement. (5)
2. (a) What is meant by air pollution? (3)
(b) What are the common pollutants in our air? Describe their sources from
which they originate? (5)
(c) Discuss the effect of oxides of nitrogen and sulphur in the atmosphere
on living organisms. (6)
(d) Name materials that acts as sink for the gases, what other measures would
you suggest to control these gases in the atmosphere? (6)
3 (a) Nitrogen trifluoride, NF₃, boils at -129°C and is devoid of Lewis basicity. (4)
By contrast the lower molecular mass compound NH₃ boils at 33°C and
is well known as Lewis base.
(i) Describe the origin of this very large difference in volatility.
(ii) Describe the probable origin of this difference in basicity.
(b) Arrange H₂O, H₂S, H₂Se in order of (4)
(i) Increasing acidity
(ii) Increasing basicity towards a hard acid such as proton.
Suggest suitable reasons for selecting your order.
(c) Write balance chemical equations for the formation of pure silicon from
crude silicon via silane (4)
(d) Ammonia can be prepared by (4)
(i) The Hydrolysis of Li₃N
(ii) The high temperature, high pressure reduction of nitrogen
by hydrogen.
Give balanced equation in each method starting with nitrogen, lithium and hydrogen
as appropriate and account for the lowest cost of the second method.
(e) Solid PCl₅ is an ionic compound of PCl₄⁺ cations and PCl₆⁻ anions but the
vapour is molecular.
What shape of ions would you propose on the bases of VSEPR model? (4)
4(a) What do you understand by the term thermodynamics? Discuss its scope
and limitations. (4)
(b) Explain the following terms: (4)
(i) Reversible and irreversible processes
(ii) Isothermal and adiabatic process.
(c) What is the second law of thermodynamics? Discuss the conditions under
which heat can be converted to work. (4)
(d) State and explain the thermodynamic terms: “Work function” and
“Free energy”. (4)
(e) State Clausius and Clapeyron equation? Comment on its applications. (4)
5. (a) Describe the main features of Crystal Field Theory. (4)
(b) Define and explain the terms: Crystal Field splitting, high spin (3)
Complexes, low spin complexes spectrochemical series.
(c) How crystal field theory can explain the spectral and magnetic properties
of coordination compounds? (3)
(d) Compounds containing the Sc⁺³ ions are colourless, whereas those
containing the Ti⁺³ ions are coloured. Explain. (2)
(e) Determine the molecular orbital bond orders of O₂, Cl₂ NO⁺ from the
Molecular orbital configuration and compare the values with the bond
orders determines from Lewis structure. (4)
6. (a) Name the chief ores of iron. (2)
(b) How pig iron is extracted from hematite ore? Is this process oxidation or
reduction? Explain. (3)
(c) Give the reactions that take place in the blast furnaces at various
temperature zones during the production of pig iron. (5)
(d) What are the main impurities present in the cast iron? State their adverse
effect on the properties of iron. (4)
(e) What are carbon steels and alloys steels? State their applications. (4)
7. Write notes on four of the following: (5 x 4)
(i) Debye Huckel theory of activity coefficients.
(ii) Cement industry and the process of setting of cement.
(iii) Glass industry and ceramics
(iv) Fullerenes and their applications
(v) Silicates and their uses.
COMPULSORY Question
8. Write only the correct answer in the Answer Book. Do not reproduce the question.
(1) Interstitial alloy tungsten carbide (WC) has the rock salt structure. The description in
terms of holes in closed packed structure is given by:
(a) Closed packed C with W in octahedral holes
(b) Closed packed W with C in octahedral holes
(c) Closed packed W with C in tetrahedral holes
(d) None of these
(2) A semiconductor is a substance showing the property where electrical conductivity:
(a) Increases with increase in temperature
(b) Decrease with increase in temperature
(c) First increase and then decrease with increase in temperature
(d) None of these
(3) Thomson observed that when light of certain frequency strikes the surface of metal:
(a) Electrons move to higher energy (b) Electrons are ejected from the metal
(c) The light is totally reflected (d) The temperature of metal is increased
(e) None of these
(4) Select which one is n-type of semiconductor:
(a) Arsenic doped Germanium (b) Gallium doped Germanium
(c) Silicon doped Germanium (d) None of these
(5) Which one of the following schemes for repeating pattern of closed packed planes are
not ways of generating closed packed lattices:
(a) ABCABC…… (b) ABABA……
(c) ABCCB…… (d) None of these
(6) The complex ion [Pd(NH₃)₄]⁺² exists in:
(a) Square planar (b) Tetrahedral (c) Octahedral
(d) Trigonal pyramidal (e) None of these
(7) Magnetic moments (μ_eff) is related to the number of unpaired electrons (n) by the
relationship:
(a) μ_eff = [n(n + 2)]¹/² (b) μ_eff = (n + 2)¹/²
(c) μ_eff = [n(n + 1)]¹/² (d) μ_eff = (n² + 1)¹/²
(8) Magnetic moments are measured in units of:
(a) Ampere meter⁻¹ (b) Bohr magneton
(c) Volt meter⁻¹ (d) Coulomb meter⁻²
(9) The transition elements show less reactivity because of:
(a) High heats of vaporization (b) Low ionization energy
(c) High heats of solvation (d) None of these
(10) Mn⁺⁷ in the form of KMnO₄ is violet in colour due to transition of electrons from:
(a) s to s orbital (b) d to d orbital
(c) p to d orbital (d) None of these
(11) The oxidation number of iron in [Fe(CN)₆]⁴⁻ is:
(a) 2 (b) 3 (c) 4 (d) 6 (e) None of these
(12) TiCl₃ is used as catalyst for the:
(a) Oxidation of ethanol to acetaldehyde
(b) Polymerization of ethene to polythene
(c) Manufacture of ammonia
(d) Oxidation of ammonia to nitric oxide
(e) None of these
(13) Interstitial compounds are crystalline solids in which interstices in the crystals lattice
of metal is occupied by:
(a) Atoms of transition elements
(b) Metals atoms having large atomic size
(c) Non metals having small atomics sizes
(d) Atoms of non metals that are highly reactive
(14) If the wave length of electron wave is infinite the electron must be:
(a) Moving with very high velocity
(b) Moving with low velocity
(c) Stationary
(d) None of these
(15) The reaction of NO₂⁻ as an oxidizing agent on lowering the pH of the medium
generally:
(a) Increases (b) Decreases
(c) Have an effect (d) None of these
(16) Predict the stability of the compounds CaI₂ and NaI₃ with respect to its elements:
(a) NaI₃ is more stable (b) CaI₂ is more stable
(c) CaI₂ is less stable (d) CaI₂ and NaI₃ are equally stable
(17) Helium is present in low concentration in the atmosphere even though it is the second
most abundant element in the universe because:
(a) It has decomposed with time
(b) It has reacted with other elements
(c) It is light and its velocity is high
(d) None of these
(18) Carbon mono oxide is one of the most abundant pollutants and widely distributed
in air. But its global level does not seem to be changing because:
(a) CO is oxidized by oxygen to CO₂
(b) CO is reduced by other chemicals to carbon particles
(c) Polar CO is dissolved readily in water
(d) None of these
(19) Some batteries are constructed in such a way that the oxidation reduction product
remains separated during the discharge reaction. These batteries:
(a) Can not be recharged (b) Can be recharged
(c) Have long life (d) None of these
(20) Aluminosilicates are largely responsible for the rich variety of the mineral world they
are compounds:
(a) When aluminum atom is embedded between silicates groups
(b) When aluminum atoms replaces some of the silicon atoms in silicates
(c) Of aluminum having no silicon atoms but structurally is similar to silicates
(d) None of these
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CHEMISTRY, PAPER-II
Attempt FIVE questions in all, Including Questions No.8 which is COMPULSORY, All questions carry EQUAL marks.
1. (a) How MOT is applied to explain ionic character of bond in heteronuclear
Diatomic molecule? Give suitable examples. (10)
(b) Which of the following species is possible to exist? Give reason. (5)
(i) NF₅ (ii) PF₅
(c) What are alkaloids? Write name and formulae of any five important alkaloids. (5)
(a) Define order of a reaction? Describe one method of determining the order
of a Reaction. (10)
(b) Show that in first order reaction, time required to complete half of a Reaction is:
(2 x 4 = 8)
(i) Independent of initial concentration.
(ii) Inversely proportional to rate constant.
(c) What are units of rate constant of 1ˢᵗ order reaction? (2)
(a) What are hybrid orbitals? Discuss conditions of their formation. (8)
(b) Suggest reasons for the following statements: (3 x 2 = 6)
(i) Cyclooctatetraene does not show resonance while benzene shows.
(ii) O-benzoic acid is more acidic than its para isomer.
(iii) Why Benzene diazonium chloride shows coupling reaction with
N,N-dimethylaniline but not with N,N,2,6-tetramethylaniline.
(c) Draw staggered, gauche, semi eclipsed and fully eclipsed conformers of
the following compounds. And arrange them in order of stabilities with
Reasoning. (6)
(i) CH₃ – CH – CH – CH₃ (ii) CH₃ – CH – CH – CH₃
| | | |
Br Br OH OH
(a) What happens when CH₃MgI is treated with following reagents and the
Product hydrolyzed? (10)
(i) formaldehyde (ii) ethylene oxide (iii) Acetaldehyde
(iv) Acetone (v) Carbon dioxide
(b) Discuss the phenomenon of chain lengthening and shortening of aldoses. (10)
(a) Complete the following reactions with mechanisms: (10)
(i) 2 [Benzene Ring with CHO] + NaCN ───> ?
AlCl₃
(ii) [Benzene Ring] + CH₃Cl ──────> ?
(b) What is Iodoform test? Discuss its usefulness for the detection of Acetyl
group (CH₃CO⁻). (5)
(c) Define the term antibiotics? Describe their chelating property. (5)
(a) What are Azo dyes? Discuss their chemistry with special reference to
Methyl Orange and Congo red. (12)
(b) Describe the synthesis of 1,3,5 tribromo benzene from aniline? Explain
why it can not be synthesized by direct bromination of benzene. (3)
(c) Which of the following species is better hydride donor in Cannizzaro
Reaction. (2)
O⁻ O⁻
| |
(i) R ── C ── H (ii) R ── C ── H
| |
O⁻ OH
(d) Define the terms Enantiomer, Diastereomer with example. (3)
7. (a) Differentiate between the following terms (3 x 3 = 9)
(i) Fats and oils
(ii) Hydrolytic and oxidative rancidification
(iii) Saponification and Iodine number.
(b) Which of the following solvent is more useful for the synthesis of (3)
Grignard reagent? Give reason.
(i) Ether (ii) THF
(c) Describe the mechanism and synthetic application of Reformatsky reaction. (8)
COMPULSORY Question
8. Write only the correct answer in the Answer Book. Do not reproduce the
question. (20)
(A) Choose the suitable answer from the given options.
(1) Glycogen is also called as:
(a) Plant starch (b) Animal starch
(c) a & b (d) None of these
(2) Cupric ion complexed with citrate ion is known as:
(a) Fehling reagent (b) Benedict reagent
(c) Tollens’ reagent (d) None of these
(3) Naturally occurring fructose is also called as:
(a) Levulose (b) Dextrose
(c) Ribose (d) b & c
(e) None of these
(4) Aniline shows two absorption maxima in U.V. region:
(a) 200, 250 mμ (b) 190, 280 mμ
(c) 230, 280 mμ (d) 230, 290 mμ
(5) The hybridization in case of the CO₃⁻² molecule will be:
(a) SP (b) SP³ (c) dSP³ (d) None of these
(6) 2NO + O₂(g) ──────> 2NO₂(g) is an example of:
(a) 1ˢᵗ order reaction (b) Second order reaction
(c) Zero order (d) None of these
(7) Which of the following carbonate is water insoluble:
(a) Na₂CO₃ (b) K₂CO₃ (c) (NH₄)₂CO₃
(d) ZnCO₃ (e) None of these
(8) What will be the colour of CdS:
(a) Brownish (b) Yellow (c) Brownish black
(d) Black (e) None of these
O COOH
‖ Lactic acid Dehydrogenase |
(9) CH₃ ─ C ─ COOH ─────────────────────────────> HO ── C ── H
NADH |
CH₃
S-(+)-lactic acid
is an example of:
(a) Stereospecific reaction (b) Cannizzaro reaction
(c) Stereoselective reaction (d) Strecker reaction
(10) Heat of Adsorption in case of Physical adsorption is:
(a) 10 k cal (b) 14 k cal (c) 20 k cal
(d) 5 k cal (e) None of these
(B) Write only True or False in the Answer Book. Do not reproduce the statements.
(11) HNO₂ is stronger acid than HNO₃.
(12) Organometallic compounds are nucleophile.
(13) The substance that concentrates at the surface is called Adsorbent.
(14) SrSO₄ is water soluble.
(15) Ethyl alcohol has higher b.p than ethanethiol.
(16) Alkaloids are optically active.
(C) Suggest the most suitable word for each of the following statements.
(17) Water has total ___ pairs of electron pairs.
(18) 1,2-dimethyl cyclo___ane has stable isomer.
(19) The stereochemis___ A B₂ E₂ will be.
(20) Green vitriol is ofte___ named.
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