Kerala PSC Work Assistant, Assistant Chemist & Analyst Key

Question 1

What is the shortest wavelength line (in nm) in the Lyman series of hydrogen spectrum ?

A

91.2 nm

B

22.6 nm

C

121.5 nm

D

34.2 nm

Question 2

The dipole moment of HCl is 1.03 D and distance between atoms is 127 pm. What is the percentage ionic character of HCl bond ?

A

6.09 %

B

60.9 %

C

609.11%

D

16.9 %

Question 3

Calculate the formal charge of S atom in SO₂.

A

+1

B

–1

C

0

D

+4

Question 4

Which of the following molecules has highest value of percentage s-character for the central atom ?

A

XeO₃

B

SF₆

C

BeF₂

D

SF₄

Question 5

Wave functions of electrons in atoms and molecules are called

A

orbit

B

orbitals

C

probability

D

all the above

Question 6

A

A)

B

B)

C

C)

D

D)

Question 7

The electronic configuration of an element is 1s² 2s² 2p⁶ 3d⁵ 4s¹. This represent its

A

excited state

B

ground state

C

cationic form

D

anionic form

Question 8

The set representing correct order of first ionization energy is

A

K > Na > Li

B

Be > Mg > Ca

C

B > C > N

D

Ge > Si > C

Question 9

Halogen that can be easily reduced

A

I₂

B

Br₂

C

Cl₂

D

F₂

Question 10

The number of P-O-P bonds in cyclic metaphosphoric acid is

A

zero

B

two

C

three

D

four

Question 11

Which among the following is an organometallic compound ?

A

Lithium methoxide

B

Lithium acetate

C

Lithium dimethylamide

D

Methyl lithium

Question 12

A

A)

B

B)

C

C)

D

D)

Question 13

K₃[Al(C₂O₄)] is called

A

Potassium aluminooxalate

B

Potassium trioxalato aluminate(III)

C

Potassium aluminium(III) oxalate

D

Potassium trioxalatoaluminate(VI)

Question 14

A compound with molecular mass 112 is transparent in UV spectrum. In infrared spectrum it shows two bands at 2940 and 1464 cm^–1. In the NMR it forms a singlet at 8.48δ. Identify the compound.

A

Cyclooctane

B

Octane

C

Heptane

D

Benzene

Question 15

The complex ion [Cr(H₂O)]²⁺ has d orbital electronic transition with energy of 169 kJ/mol. At what wavelength does the [Cr(H₂O)]²⁺ ion absorb ?

A

707.4 nm

B

7.07 nm

C

2.81 nm

D

281 nm

Question 16

The method of electrolytic refining is not suitable for the extraction of

A

Aluminium

B

Copper

C

Mercury

D

Silver

Question 17

Biological function of carbonic anhydrase and carboxy peptidase A respectively are

A

Interconversion of CO₂ and carbonates and gene regulation

B

Gene regulation and hydrolysis of peptide bond

C

Gene regulation and interconversion of CO₂ and carbonates

D

Interconversion of CO₂ and carbonates and hydrolysis of peptide bond

Question 18

A

a-ii, b-i, c-iii

B

a-iii, b-i, c-ii

C

a-ii, b-iii, c-i

D

a-iv, b-iii, c-ii

Question 19

The number of ATP molecules hydrolysed when 3 Na⁺ ions pumped out of cell and 2 K⁺ pumped into the cell

A

1

B

2

C

4

D

3

Question 20

In the active sites of many enzymes, metals are coordinated by the aminoacid histidine, which element in histidine donates the electrons that form the coordinate bond ?

A

Carbon

B

Oxygen

C

Nitrogen

D

Sulfur

Question 21

Which of the following is not refined by zone refining method ?

A

Germanium

B

Silicon

C

Gallium

D

Gold

Question 22

A

A)

B

B)

C

C)

D

D)

Question 23

The organometallic compound follows 18 electron rule, the hapticities of two cyclopentadienyl groups are [W(C₂H₅)₂(CO)₂]

A

5 and 5

B

3 and 5

C

3 and 3

D

1 and 5

Question 24

A

A)

B

B)

C

C)

D

D)

Question 25

Which of the following is not an organometallic compound ?

A

Ferrocene

B

Cis-platin

C

Zieses salt

D

Grignard reagent

Question 26

A key feature of Fischer-Tropsch process is

A

hydrocarbon formation

B

alkene hydrogenation

C

alkene polymerization

D

hydroformylation

Question 27

Accuracy expresses the

A

correctness of an experiment

B

feasibility of an experiment

C

deviation from experiment

D

reproducibility of an experiment

Question 28

In an experiment values 2.2, 2.3 and 2.4 are obtained while the true value is 4.6. Now if we double each value then

A

Precision is increased but accuracy is decreased

B

Both precision and accuracy are increased

C

Accuracy is increased but precision remains unchanged

D

Both precision and accuracy are decreased

Question 29

The thermogram in differential thermal analysis is a plot of

A

dw/dt Vs Temperature

B

△T Vs Temperature

C

△H Vs Temperature

D

T Vs Volume

Question 30

The donor atom in EDTA are

A

Two N and two O

B

Two N and four O

C

Four N and two O

D

Three N and two O

Question 31

Limiting current in polarography depends on

A

Residual current

B

Diffusion current

C

Kinetic current

D

All the above

Question 32

The material of cathode in Hollow cathode lamp constructed in AAS

A

Tungsten

B

Quartz

C

Element to be investigated

D

All the above

Question 33

Cell constant is

A

length × area

B

length/area

C

area/length

D

none of the above

Question 34

A

A)

B

B)

C

C)

D

D)

Question 35

Free radicals are detected by the

A

Mass spectra

B

CIDNP

C

UV spectra

D

Mossbauer spectroscopy

Question 36

A

A)

B

B)

C

C)

D

D)

Question 37

In E2 reaction the dihedral angle of synperiplanar conformation is

A

0°

B

90°

C

120°

D

180°

Question 38

Which of the following is not an electrophile ?

A

CH₄

B

SO₃

C

Br+

D

BF₃

Question 39

Homolytic fission for generation of free radical is favoured most in bond

A

C – C

B

O – O

C

C – O

D

C – N

Question 40

A

A)

B

B)

C

C)

D

D)

Question 41

For the structure E-1-bromo-1-chloro propene, the correct statement is

A

–CH₃ and –Cl are on same side of double bond

B

–CH₃ and –Cl are on opposite side of double bond

C

–Br and –H are on opposite side of double bond

D

–Cl and –H are on same side of double bond

Question 42

The correct R-S notation for the structure 3-chlorobutane-2-ol is

A

1R, 3S

B

1R, 4S

C

2R, 3S

D

2S, 3R

Question 43

An aqueous solution of 6.3 g oxalic acid dehydrate is made upto 250 ml. The volume of 0.1 N NaOH required to completely neutralize 10 ml of this solution is

A

10 ml

B

20 ml

C

40 ml

D

4 ml

Question 44

Wurtz reaction on a mixture of ethyl iodide and n-propyl iodide does not yield the hydrocarbon

A

n-butane

B

n-propane

C

n-pentane

D

n-hexane

Question 45

Alcoholic solution of KOH is used for

A

Dehydrogenation

B

Dehalogenation

C

Dehydration

D

Dehydrohalogenation

Question 46

A complex has a composition corresponding to formula CoBr₂Cl.4NH₃. What is the structural formula if conductance measurements show two ions per formula unit ? Silver nitrate solution gives an immediate precipitate of AgCl but no AgBr.

A

[CoBrCl(NH₃)₄]Br

B

[CoCl(NH₃)₄]Br₂

C

[CoBr₂Cl(NH₃)₄]

D

[CoBr₂(NH₃)₄]Cl

Question 47

Which among the following is not aromatic ?

A

Cyclopentadienyl anion

B

Cycloheptadienyl cation

C

Cyclopentadienyl cation

D

Cyclopentadienyl iron

Question 48

A

A)

B

B)

C

C)

D

D)

Question 49

Which of the following reaction cannot be employed to prepare alkyl halides ?

A

Darzen reaction

B

MPV reduction

C

Markonikofs addition of HCl to an unsymmetrical alkene

D

Halogenation of alkenes

Question 50

Aniline reacts with glycerol in presence of sulphuric acid and nitrobenzene as an oxidizing agent. Which among the following statement is more correct ?

A

Bayer Villiger Oxidation and the product is quinoline.

B

Rosenmunds reduction and the product is quinoline.

C

Paal Knoor synthesis and the product is quinoline.

D

Skraup reaction and the product is quinoline.

Question 51

Among the following reactions and the final product, which pair does not match ?

A

Cumene reactions gives phenol and acetone

B

Kolbe-Schmidt reaction gives ortho-hydroxy benzoic acid

C

Fries rearrangement gives methoxybenzoic acid

D

Bischler-Napieralski reaction gives isoquinolines

Question 52

Phenol is dissolved in caustic soda solution along with CO₂ gas at about 398 K and 4 – 7 bar pressure gives which of the following compound ?

A

Sodium phenoxide

B

Cumene hydroperoxide

C

Phthalic acid

D

None of the above

Question 53

Glycerol on periodic acid oxidation gives

A

HCHO + 2HCOOH

B

2HCHO + HCOOH

C

2CH₃OH + HCOOH

D

CH₃OH + 2HCOOH

Question 54

A

Propylamine

B

Ethylamine

C

Propanoic acid

D

None of these

Question 55

Identify the wrong statement regarding carbocation rearrangement.

A

Tertiary alkyl groups generally undergo 1,2-shifts to the electron-deficient centres more readily than primary and secondary alkyl groups do.

B

The bond breaking and making are concerted in the 1, 2-shift of a methyl group in carbocations.

C

The transition structure for a 1,2-shift to an electron-deficient centre is regarded as a cyclic three-centre two-electron system.

D

The configuration of a carbon centre undergoing a 1,2-shift in a carbocation is not retained.

Question 56

Etard reaction in the following is

A

Oxidation of toluene to benzaldehyde by chromyl chloride

B

Oxidation of toluene to benzaldehyde by alkaline KMnO₄

C

Dry distillation of calcium benzoate

D

Reaction of benzene with Cl₂ in the presence of UV light

Question 57

The chlorination of toluene in pressure of ferric chloride gives mostly

A

Meta-chlorotoluene

B

Benzyl chloride

C

Dichlorobenzene

D

o- and p-chlorobenzene

Question 58

In the nitrating mixture, HNO₃ acts as which among the following ?

A

Base

B

Acid

C

Reducing agent

D

Catalyst

Question 59

Which of the following is not a correct statement on aromatic electrophilic substitution reactions ?

A

– CN is deactivating and m-directing

B

– Br is activating and o, p-directing

C

– OCH₃ is activating and o, p-directing

D

– NH₂ is activating and o, p-directing

Question 60

Identify the wrong statement.

A

The base-catalysed α-halogenation of propanone is first order with respect to base.

B

The rate constant for the base-catalysed α-halogenation of propanone decreases in the order Cl₂ > Br₂ > I₂.

C

The base-catalysed α-halogenation of propanone proceeds easily to give 1, 1, 1-trihalopropanone, an unsymmetric polyhalo ketone.

D

Polyhalogenation of propanone is difficult under acidic conditions, but the products are the same as those obtained under basic conditions.

Question 61

Identify the product of Knoevenagel reaction.

A

Primary and secondary amine

B

Unsaturated acyclic system

C

Beta keto ester

D

Acid anhydride

Question 62

Identify the starting reagents in Dieckman Condensation ?

A

One molecule with an ester towards the end of the molecule

B

Two molecules of ester

C

One molecule of ester and enolate

D

One molecule with two ester towards the end of the molecule

Question 63

Identify the wrong articulation about Claisen condensation.

A

A β-keto ester is formed and the product undergo further deprotonation by the strong base.

B

Claisen condensation involves the condensation of two esters in the presence of strong base.

C

A strong base is required to remove H+ from an α-H position of the starting ester.

D

All the above statements are correct

Question 64

A carbonyl compound reacts with an ylide to form an alkene. Identify the reaction.

A

Aldol reaction

B

Wittig reaction

C

Wolf Kishner reaction

D

Reformatsky reaction

Question 65

Which of the following compounds does not contain an active methylene group ?

A

Ethylacetoacetate

B

Diethylmalonate

C

Diethylfumarate

D

Cyanoacetic ester

Question 66

The approximate total energy of an ideal monoatomic gas in kJmol^–1 at 27°C is

A

1.67

B

16.7

C

167

D

1670

Question 67

At what temperature will helium atoms have the same rms velocity as hydrogen molecule at 300K ?

A

150K

B

300K

C

450K

D

600K

Question 68

Give the correct statement about the viscosity of liquids.

A

increases with rise in temperature and increases with increase in pressure

B

decreases with rise in temperature and increases with increase in pressure

C

decreases with rise in temperature and decreases with increase in pressure

D

increases with rise in temperature and decreases with increase in pressure

Question 69

A

A)

B

B)

C

C)

D

D)

Question 70

Number of effective atoms per unit cell in a bcc system is

A

1

B

2

C

3

D

4

Question 71

The rule that relates the molar heat of vaporisation of a liquid with its normal boiling point is

A

Raoult’s

B

Henry’s

C

Trouton’s

D

Kelvin’s

Question 72

Calculate the approximate pOH of 0.03 M solution of HCl at 25°C is

A

3

B

7.48

C

12.48

D

14

Question 73

A

A)

B

B)

C

C)

D

D)

Question 74

A buffer is most effective in the range of pH values between

A

pK –1 and pK +1

B

pK –2 and pK +2

C

pK –3 and pK +3

D

pK – 4 and pK +4

Question 75

In the conversion of nitrogen to ammonia at 400°C, what is the standard Gibbs energy in kJmol^–1 if the equilibrium constant for the formation of ammonia is 10^–4 at 1 bar pressure ?

A

1

B

10

C

20

D

200

Question 76

A

A)

B

B)

C

C)

D

D)

Question 77

Which is not an application of Nernst distribution law ?

A

solvent extraction

B

study of complex ions

C

study of association and dissociation of solute

D

study of partial molar properties

Question 78

5.2 moles of an ideal gas expand reversibly from a volume of 8 lit to 80 lit at 300K. Calculate the approximate change in entropy in JK^–1

A

640

B

100

C

320

D

10

Question 79

Work done in a closed system in an adiabatic process is equal to the increase in _______ of the system.

A

Internal energy

B

enthalpy

C

entropy

D

residual entropy

Question 80

The value of Joule Thomson coefficient for an ideal gas is

A

negative

B

positive

C

zero

D

unpredictable

Question 81

Calculate the approximate entropy change in JK^–1mol^–1 if n-hexane boils at 68.7°C at 1 bar pressure if the molar enthalpy of vaporisation is 28850 Jmol^–1.

A

8.4

B

84.4

C

844.4

D

8444

Question 82

Calculate the approximate amount of work if one mole of an ideal gas at 27°C isothermally expands from a volume of 10 lit to 20 lit against a constant external pressure of 1 atm.

A

10 kJ

B

1 kJ

C

0.10 kJ

D

27 kJ

Question 83

The term for the activity of a gas which serves as a thermodynamic counterpart of gas pressure is

A

ensemble

B

phase space

C

fugacity

D

parachor

Question 84

What percentage of reactant will be left at the end of 25 mins, if the reaction is of first order with a half-life period of 5 mins ?

A

25

B

31

C

3.1

D

50

Question 85

A

A)

B

B)

C

C)

D

D)

Question 86

In Arrhenius equation, k = Ae – (E_a/RT) the pre exponential factor has the same unit as that of

A

activation energy

B

temperature

C

rate constant

D

time

Question 87

Which of the following is not an assumption in the derivation of Langmuir adsorption isotherm ?

A

Only a monolayer is developed

B

Adsorbed gas behaves ideally

C

Adsorbed gas molecules are localised

D

There is lateral interaction between absorbate molecules

Question 88

The Michalis – Menton mechanism account for the

A

chain polymerisation reaction

B

stepwise polymerisation reaction

C

first order kinetics of gas phase reactions

D

dependence of rate on the concentrations of substrate and enzyme

Question 89

The experimental effect of increase in conductance of a strong electrolyte in aqueous solution to a certain limiting value with increase in potential is called _______ effect.

A

Debye

B

Falkenhagen

C

Walden

D

Wien

Question 90

Calculate the ionic strength of 0.2 molal BaCl² solution.

A

0.2

B

0.4

C

0.6

D

0.8

Question 91

A

A)

B

B)

C

C)

D

D)

Question 92

A zinc rod is dipped in a 0.1 M solution of ZnSO₄ at 25°C and if the salt undergoes 100% dissociation, calculate the approximate potential of electrode if the standard potential E⁰(Zn²⁺/Zn) is –0.76V.

A

+0.76

B

–0.76

C

–0.79

D

+0.79

Question 93

Calculate the potential of the cell Zn, Zn²⁺ (1M)|Fe²⁺ (1M); Pt, if the respective standard reduction potential of half-cell are respectively –0.76V and +0.77V.

A

+0.76V

B

–0.77V

C

+1.53V

D

+0.01V

Question 94

A

A)

B

B)

C

C)

D

D)

Question 95

If the rotational constant B of ¹²C¹⁶O is 3.8 cm^–1, the position of first rotational line in its spectrum in cm^–1 is

A

1.9

B

3.8

C

7.6

D

15.2

Question 96

A

A)

B

B)

C

C)

D

D)

Question 97

In the vibrational Raman spectrum separation of each line from the centre of the excitation line gives the Raman active ____ vibrational frequency of the molecule.

A

hot band

B

first overtone

C

second overtone

D

fundamental

Question 98

A

A)

B

B)

C

C)

D

D)

Question 99

In a 60 MHz instrument a chemical shift value of 2 ppm from TMS is equivalent to _______ Hz.

A

30

B

60

C

120

D

1200

Question 100

The number of lines in the EPR spectrum of ¹²CF₂H radical is

A

1

B

2

C

4

D

6

028/2022 - Work Assistant, Assistant Chemist & Analyst