KCET – CHEMISTRY – 2020

[Pages:8]KCET ? CHEMISTRY ? 2020

VERSION CODE: D-3

Chemistry KCET-2020 Paper Analysis (Version Code: D-3 )

Chapter Name

No. of Questions

Questions Number in the Paper

Some Basic Concepts of Chemistry

1

47

Structure of Atom

1

48

Classification of Elements and

1

49

Periodicity in Properties

Chemical Bonding and Molecular Structure

4

20, 36, 52, 53

States of Matter

1

51

Thermodynamics

1

54

Equilibrium

1

50

Redox Reactions

2

24, 55

Hydrogen

1

58

The s-Block Elements

1

57

The p-Block Elements

1

56

Organic Chemistry

1

59

Hydrocarbons

1

60

Environmental Chemistry

1

1

The Solid State Solutions Electrochemistry Chemical Kinetics Surface Chemistry Isolation of Elements p-Block Elements d- and f- Block Elements Coordination Compounds Haloalkanes and Haloarenes Alcohols, Phenols and Ethers Aldehydes, Ketones and Acids Amines & Diazo Compounds Biomolecules Polymers Chemistry in Every Day Life

3

2, 3, 4

2

7, 6

4

5, 8, 9, 10

3

11, 12, 13

2

14, 15

2

16, 17

4

18, 19, 22, 21

2

23, 25

3

26, 27, 28

3

29, 30, 31

3

32, 33, 34

2

35, 37,

2

38, 39

3

40, 41, 42

2

43, 44

2

45, 46

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1. Which of the following is NOT a green house gas?

(A) CO2 Ans: (B)

(B) O2

(C) NO2

(D) CFC

2. A metal exists as an oxide with formula M0.96 O. Metal M can exist as M+2 and M+3 in its oxide M0.96 O. The percentage of M+3 in the oxide is, nearly

(A) 4.6%

(B) 5%

(C) 9.6%

(D) 8.3%

Ans: (D)

3. A metal crystallises in face centred cubic structure with metallic radius 2A0 . The volume of

the unit cell (in m3) is

(A) 6.4 ? 10-29

(B) 4 ? 10-9

(C) 6.4 ? 10-30

(D) 4 ? 10-10

Ans: (A)

4. Silicon doped with gallium forms (A) both n and p type semiconductor (C) p ? type semiconductor

Ans: (C)

(B) an intrinsic semiconductor (D) n ?type semiconductor

5. The pair of electrolytes that possess same value for the constant (A) in the Debye ? Huckel ?

Onsagar equation, m = om - A C is

(A) NH4Cl, NaBr Ans: (A)

(B) NaBr, MgSO4 (C) NaCl, CaCl2

(D) MgSO4, Na2SO4

6. Which of the following pair of solutions is isotonic? (A) 0.001 M A 2(SO4 )3 and 0.01M BaC 2 (B) 0.001M CaC 2 and 0.001 M A 2 (SO4)3 (C) 0.01M BaC 2 and 0.001M CaC 2 (D) 0.01M BaC 2 and 0.015M NaC

Ans: (D)

7. Solute `X' dimerises in water to the extent of 80%. 2.5g of `X' in 100g of water increases the

boiling point by 0.3 ?C. The molar mass of `X' is [Kb = 0.52 K kgmol-1]

(A) 52

(B) 65

(C) 26

(D) 13

Ans: (C)

8.

Given

Eo Fe+3 / Fe+2

= +0.76V

and

Eo I 2/ I-

= +0.55V .

The

equilibrium

constant

for

the

reaction

taking

place

in

galvanic

cell

consisting

of

above

two

electrodes

is

2.303RT F

= 0.06

(A) 1 ? 109

(B) 3 ? 108

(C) 5 ? 1012

(D) 1 ? 107

Ans: (D)

9. If an aqueous solution of NaF is electrolyzed between inert electrodes, the product obtained

at anode is

(A) H2 Ans: (C)

(B) Na

(C) O2

(D) F2

10. In which of the following cases a chemical reaction is possible? (A) AgNO3 solution is stirred with a copper spoon. (B) Conc. HNO3 is stored in a platinum vessel (C) gold ornaments are washed with dil HC

(D) ZnSO4(aq) is placed in a copper vessel Ans: (A)

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11. The time required for 60% completion of a first order reaction is 50 min. The time required

for 93.6% completion of the same reaction will be

(A) 83.8 min

(B) 50min

(C) 150min

(D) 100min

Ans: (C)

12. For an elementary reaction 2A + 3B 4C + D the rate of appearance of C at time `t' is 2.8 ? 10-3 mol L-1S-1. Rate of disappearance of B at `t', t will be

( ) (A) 3 2.8 ? 10-3 molL-1S-1 4

( ) (B) 2 2.8 ? 10-3 molL-1S-1

( ) (C) 1 2.8 ? 10-3 molL-1S-1 4

( ) (D) 4 2.8 ? 10-3 molL-1S-1 3

Ans: (A)

13. The rate constant of a reaction is given by k = PZe-Ea/RT under standard notation. In order to

speed up the reaction, which of the following factors has to be decreased?

(A) Both Z and T Ans: (B)

(B) Ea

(C) T

(D) Z

14. A sol of AgI is prepared by mixing equal volumes of 0.1 M AgNO3 and 0.2M KI, which of the following statement is correct? (A) Sol obtained is a positive sol with Ag+ adsorbed on AgI (B) Sol obtained is a positive sol with K+ adsorbed on AgI (C) Sol obtained is a negative sol with I- adsorbed on AgI

(D) Sol obtained is a negative sol with NO3- adsorbed on AgI.

Ans: (C)

15. During Adsorption of a gas on a solid

(A) G > 0, H > 0, S > 0 (C) G < 0, H > 0, S > 0 Ans: (D)

(B) G < 0, H < 0, S > 0 (D) G < 0, H < 0, S < 0

16. Copper is extracted from copper pyrites by

(A) Reduction by coke

(B) Electrometallurgy

(C) Auto reduction

(D) Thermal decomposition

Ans: (C)

17. Function of potassium ethylxanthate in froth flotation process is to make the ore

(A) hydrophobic

(B) hydrophilic

(C) heavier

(D) lighter

Ans: (A)

18. Sulphide ore on roasting gives a gas X. X reacts with Cl2 in the presence of activated charcoal to give Y. Y is

(A) S2C 2

(B) SC 2

(C) SOC 2

(D) SO2C 2

Ans: (D)

19. Aqueous solution of a salt (A) forms a dense white precipitate with BaC 2 solution. The

precipitate dissolve in dilute HCl to produce a gas (B) which decolourises acidified KMnO4 soltion.

A and B respectively are:

(A) BaSO4, H2S Ans: (D)

(B) BaSO3, H2S

(C) BaSO4, SO2

(D) BaSO3, SO2

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20. Bond angle in PH4+ is more than that of PH3. This is because

(A) PH4+ has square planar structure

(B) PH3 has planar trigonal structure

(C) hybridisation of P changes when PH3 is converted to PH4+

(D) lonepair - bond pair repulsion exists in PH3 Ans: (D)

21. Incorrectly matched pair is:

(A) XeF4 ? tetrahedral (C) XeOF4 ? square pyramidal Ans: (A)

(B) XeF6 ? distorted octahedral (D) XeO3 ? pyramidal

22. Phosphorus pentachloride (A) on hydrolysis gives an oxo acid of phosphorus which is a good reducing agent (B) has all the five equivalent bonds (C) exists as an ionic solid in which cation has octahedral structure and anion has tetrahedral structure (D) on hydrolysis gives an oxo acid of phosphorus which is tribasic.

Ans: (D)

23. Identify the set of paramagnetic ions among the following: (A) Ni2+, Cu2+, Zn2+ (B) Ti3+, Cu2+, Mn3+ (C) Sc3+, Ti3+, V3+

Ans: (B)

(D) V2+, Co2+, Ti4+

24. How many moles of acidified K2Cr2O7 is required to liberated 6 moles of I2 from an aqueous solution of I-?

(A) 1

(B) 0.25

(C) 0.5

(D) 2

Ans: (D)

25. Cu2Cl2 and CuCl2 in aqueous medium (A) Stability of Cu2Cl2 is equal to stability of CuCl2 (B) Both are unstable

(C) Cu2Cl2 is more stable than CuCl2 (D) CuCl2 is more stable than Cu2Cl2 Ans: (D)

26. The co-ordination number of Fe and Co in the complex ions, [Fe(C2O4)3]3- and [Co(SCN)4]2are respectively:

(A) 6 and 8

(B) 4 and 6

(C) 6 and 4

(D) 3 and 4

Ans: (C)

27. Number of stereoisomers exhibited by [Co(en)2Cl2]+ is

(A) 2

(B) 5

(C) 3

Ans: (C)

28. Give the IUPAC name of [Pt(NH3)4] [PtCl4] is (A) tetra ammine palatinate (II) tetra chlorido platinum (II)

(B) tetra ammine palatinate (o) tetra chlorido platinum (IV)

(C) tetra ammine platinum (II) tetra chlorido palatinate (II)

(D) tetra ammine platinum (o) tetra chlorido plantinum (IV)

Ans: (C)

(D) 4

29. Prolonged exposure of chloroform in humans may cause damage to liver. It is due to the

formation of the following compound:

(A) COCl2 Ans: (A)

(B) CH2Cl2

(C) Cl2

(D) CCl4

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30. Which of the following halide shows highest reactivity towards SN1 reaction?

(A) CH3 ? CH2Cl

(B) CH3 ? CH2 ? CH2 ? CH2I

(C) C6H5Cl

(D) C6H5CH2Cl

Ans: (D)

31.

Dry ether

MgBr + CH3NH2

X

. The number of possible isomers for the organic

compound X is

(A) 5 Ans: (C)

(B) 3

(C) 2

(D) 4

32. Which of the following on heating gives an ether as major product?

P : C6H5CH2 Br + CH3ONa

Q : C6H5ONa + CH3Br

R : (CH3)3 C - C + CH3ONa (A) Both P and R

S : C6H5CH = CHC + CH3ONa (B) Both Q and S

(C) Both P and Q

(D) Both R and S

Ans: (C)

33. The steps involved in the conversion of propan ? 2- ol to propan ? 1 ? ol are in the order

(A) heating with PC5, heating with alc. KOH, acid catalysed addition of water

(B) heating with PC5, heating with alc. KOH, hydroboration ? oxidation (C) dehydration, addition of HBr in presence of peroxide, heating with alc, KOH (D) dehydration, addition of HBr heating with aq. KOH Ans: (B)

34. Which of the following is the strongest base

(A) C- Ans: (C)

(b) OH-

(C) CH3O-

(D) CH3COO-

35.

CHO + CH3CHO (1)dil. NaOH P. The product `P' is

(2)

(A) CH = CH - CH3

(B) CH = CHCHO

CHO

(C)

CH2CHO

CHO (D)

Ans: (B)

CH2CHO

36. Which of the following has the lowest boiling point?

(A) CH3 ? CH2 ? NH2

(B) CH3 ? O ? CH3

(C) HCOOH

(D) CH3CH2OH

Ans: (B)

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37. The carbonyl compound that does not undergo aldol condensation is

(A) dichloroacetaldehyde

(B) trichloroacetaldehyde

(C) acetaldehyde

(D) acetone

Ans: (B)

38. NO

(A) Br

Br2/FeBr3

(i) NaNO2, 273 K

+

Sn/con.HCl P

Q

dil.HC R The final product R is (ii) water, warm

Br (B)

NH2 OH (C)

NO2

N2Cl

(D)

Br

Br

Ans: (A)

39. Hinsberg's reagent is (A) C6H5SO2C (C) CH3COC / pyridine

Ans: (A)

(B) C6H5SO2NH2 (D) (CH3CO)2/O pyridine

40. Which one of the following vitamins is not stored in adipose tissue?

(A) B6

(B) D

(C) E

(D) A

Ans: (A)

41. Hypothyroidism is caused by the deficiency of

(A) Adrenalin

(B) Thyroxine

(C) Glucocorticoid

Ans: (B)

(D) Vitamin B ? 12

42. C1 ? C4 glycosidic bond is NOT found in

(A) sucrose

(B) lactose

Ans: (A)

(C) starch

(D) maltose

43. Which of the following polymer has strongest intermolecular forces of attraction?

(A) Terylene

(B) Polythene

(C) Polystyrene

(D) Neoprene

Ans: (A)

44. Which of the following monomers can undergo condensation polymerization?

(A) Glycine

(B) Isoprene

(C) Propene

(D) Styrene

Ans: (A)

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45. A food additive that acts as an anti-oxidant is

(A) Saccharin

(B) Sugar syrup

(C) salt

Ans: (D)

(D) BHA

46. Which of the following is not related to drug ? enzyme interaction?

(A) antagonist

(B) co-enzymes

(C) enzyme inhibitor

(D) allosteric site

Ans: (B)

47. 0.4 g of dihydrogen is made to react with 7.1 g of dichlorine to form hydrogen chloride. The volume of hydrogen chloride formed at 273 K and 1 bar pressure is

(A) 4.54 L

(B) 90.8 L

(C) 45.5 L

(D) 9.08 L

Ans: (A)

48. With regard to photoelectric effect, identify the CORRECT statement among the following: (A) Number of e- ejected increases with the increase in the frequency of incident light. (B) Number of e- ejected increases with the increase in work function. (C) Number of e- ejected increases with the increase in the intensity of incident light. (D) Energy of e- ejected increases with the increase in the intensity of incident light.

Ans: (C)

49. The last element of the p ? block in 6th period is represented by the outer most electronic

configuration:

(A) 5f14 6d10 7s2 7p6

(B) 4f14 5d10 6s2 6p4

(C) 4f14 5d10 6s2 6p6

(D) 7s2 7p6

Ans: (C)

50. The conjugate base of NH3 is

(A) NH4OH

(B) NH2OH

Ans: (C)

(C) NH2-

(D) NH4+

51. A gas mixture contains 25% He and 75% CH4 by volume at a given temperature and pressure. The percentage by mass of methane in the mixture is approximately ____.

(A) 25%

(B) 92%

(C) 8%

(D) 75%

Ans: (B)

52. The percentage of s-character in the hybrid orbitals of nitrogen in NO2+ , NO3- and NH4+ respectively are :

(A) 33.3%, 25% , 50%

(B) 50%, 33.3%, 25%

(C) 25%, 50%, 33.3%

(D) 33.3%, 50%, 25%

Ans: (B)

53. The formal charge on central oxygen atom is ozone is

(A) 0

(B) +2

(C) +1

Ans: (C)

(D) -1

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54. When the same quantity of heat is absorbed by a system at two different temperatures T1 and T2, such that T1 > T2, change in entropies are S1 and S2 respectively. Then :

(A) S1 = S2

(B) S2 > S1

(C) S2 < S1

(D) S1 < S2

Ans: (D)

55. The oxidation number of nitrogen atoms in NH4NO3 are

(A) -3, +5

(B) +3, -5

(C) -3, -3

Ans: (A)

(D) +5, +5

56. A Lewis acid `X' reacts with LiA/H4 in ether medium to give a highly toxic gas. This gas when heated with NH3 gives a compound commonly known as inorganic benzene. The gas is

(A) B2H6

(B) B3N3H6

(C) BF3

(D) B2O3

Ans: (A)

57. The oxide of potassium that does not exist is

(A) KO2

(B) K2O2

(C) K2O3

Ans: (C)

(D) K2O

58. The metal that produces H2 with both dil HCl and NaOH (aq) is

(A) Mg

(B) Ca

(C) Fe

(D) Zn

Ans: (D)

59. Which of the following is NOT a pair of functional isomers?

(A) CH3HC2OH and CH3OCH3 (C) CH3COOH and HCOOCH3 Ans: (D)

(B) CH3CH2NO2 and H2NCH2COOH (D) C2H5OC2H5 and C3H7OCH3

60. (A) Cl

Anhydrous AlCl3

+ 6Cl2 dark, cold

X + 6HCl

Cl Cl

(B) Cl

Cl Cl

Cl (C)

Cl Cl

Cl

Cl

Cl

Cl Cl

Cl (D)

Ans: (A)

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