12

TH

STANDARD CHEMISTRY

CHAPTERS FROM 7. NUCLEAR CHEMISTRY TO 15.ISOMERISM IN ORGANIC CHEMISTRY

CHOOSE THE CORRECT ANSWER 1. The phenomenon of radioactivity was discovered by a) Madam curie b) Pierre curie c) Henry Becquerel d) Rutherford

CHOOSE THE CORRECT ANSWER 2. The most penetrating radiations are a) α rays b) β rays c) γ rays d) all are equally penetrating

CHOOSE THE CORRECT ANSWER 3. In the nuclear reaction, 92 U 238 → 82 Pb 206 , the number of α and β particles emitted are a) 7α, 5β b) 6α, 4β c) 4α, 3β d) 8α, 6β

CHOOSE THE CORRECT ANSWER 4. Which one of the following particles is used to bombard 13 Al 27 to give 15 p 30 and a neutron a) α particle b) deuteron c) proton d) neutron

CHOOSE THE CORRECT ANSWER 5. The reaction 5 B 8 → 4 Be 8 takes place due to a) α decay b) β decay c) electron capture d) positron decay

CHOOSE THE CORRECT ANSWER 6. Radioactivity is due to a) Stable electronic configuration b) Stable nucleus c) Unstable nucleus d) Unstable electronic configuration

CHOOSE THE CORRECT ANSWER 7. In the following radioactive decay, 92 x 232 → 89 y 220 , how many α and β particles are ejected.

a) 3α and 3β b) 5α and 3β c) 3α and 5β d) 5α and 5β

CHOOSE THE CORRECT ANSWER 8. 92 U 235 nucleus absorbs a neutron and disintegrates into 54 Xe 139 , 38 Sr 94 and x. What will be the product x?

a) 3 neutrons b) 2 neutrons c) α particle d) β particle

CHOOSE THE CORRECT ANSWER 9. Loss of a β-particle is equivalent to a) Increase of one proton only b) Decrease of one neutron only c) Both (a) and (b) d) None of these

CHOOSE THE CORRECT ANSWER 10. Which of the following is used as neutron absorber in the nuclear reactor?

a) Water b) Deuterium c) Some compound of uranium d) Cadmium

CHOOSE THE CORRECT ANSWER 11. The number of chloride ions that surrounds the central Na + ion in NaCl crystal is_______.

(a) 12 (b) 8 (c) 6 (d) 4

CHOOSE THE CORRECT ANSWER 12. The Bragg’s equation is (a) λ = 2d sinθ (b) nd = 2λ sinθ (c)2λ = nd sinθ (d) nλ = 2d sinθ

CHOOSE THE CORRECT ANSWER 13. A regular three dimensional arrangement of identical points in space is called (a) Unit cell (b) Space lattice (c) Primitive (d) Crystallography

CHOOSE THE CORRECT ANSWER 14. The smallest repeating unit in space lattice which when repeated over and again results in the crystal of the given substance is called (a) Space lattice (b) Crystal lattice (c)Unit cell (d) Isomorphism

CHOOSE THE CORRECT ANSWER 15. The crystal structure of CsCl is (a) Simple cubic (b) face-centred cubic (c) Tetragonal (d) Body centred cubic

CHOOSE THE CORRECT ANSWER 16. An example for Frenkel defect is (a) NaCl (b) AgBr (c) CsCl (d) FeS

CHOOSE THE CORRECT ANSWER 17. Semiconductors which exhibit conductivity due to the flow of excess negative electrons are called (a) Super conductors (b) n-type semiconductors (c) p-type semiconductors (d) Insulators

CHOOSE THE CORRECT ANSWER 18. In the Bragg’s equation for diffraction of X-rays, ’n’ represents (a) The number of moles (b) Avogadro number (c) A quantum number (d) Order of reflection

CHOOSE THE CORRECT ANSWER 19. The number of close neighbours in a body centred cubic lattice of identical spheres is (a) 6 (b) 4 (c) 12 (d) 8

CHOOSE THE CORRECT ANSWER 20. The crystals which are good conductors of electricity and heat are (a) Ionic crystals (b) Molecular crystals (c) Metallic crystals (d) Covalent crystals

CHOOSE THE CORRECT ANSWER 21. In a simple cubic cell, each point on a corner is shared by (a) One unit cell (b) Two unit cell (c) 8 unit cell (d) 4 unit cell

CHOOSE THE CORRECT ANSWER 22. The ability of certain ultra cold substances to conduct electricity without resistance is called (a) Semiconductor (b) Conductor (c) Superconductor (d) Insulator

CHOOSE THE CORRECT ANSWER 23. The total number of atoms per unit cell is bcc is (a) 1 (b) 2 (c) 3 (d) 4

CHOOSE THE CORRECT ANSWER 24. Rutile is (a) TiO 2 (b) Cu 2 O (c) MoS 2 (d) Ru

CHOOSE THE CORRECT ANSWER 25. Semiconductors are used as (a) rectifiers (b) transistors (c) solar cells (d) all the above

CHOOSE THE CORRECT ANSWER 26. An example of metal deficiency defect (a) NaCl (b) AgCl (c) CsCl (d) FeS

CHOOSE THE CORRECT ANSWER 27. The amount of heat exchanged with the surrounding at constant temperature and pressure is called a) ΔE b) ΔH c) ΔS d) ΔG

CHOOSE THE CORRECT ANSWER 28. All the naturally occuring processes proceed spontaneously in a direction which leads to a) decrease of entropy b) increase in enthalpy c) increase in free energy d) decrease of free energy

CHOOSE THE CORRECT ANSWER 29. In an adiabatic process which of the following is true?

a) q = w b) q = 0 c) ΔE = q d) PΔV =0

CHOOSE THE CORRECT ANSWER 30. When a liquid boils, there is a) an increase in entropy b) a decrease in entropy c) an increase in heat of vapourisation d) an increase in free energy

CHOOSE THE CORRECT ANSWER 31. If ΔG for a reaction is negative, the change is a) Spontaneous b) Non-spontaneous c) Reversible d) Equilibrium

CHOOSE THE CORRECT ANSWER 32. Which of the following does not result in an increase in the entropy?

a) crystallisation of sucrose from solution b) rusting of iron c) conversion of ice to water d) vaporisation of camphor

CHOOSE THE CORRECT ANSWER 33. In which of the following process, the process is always non-feasible?

a) ΔH > 0, ΔS > 0 b) ΔH < 0, ΔS > 0 c) ΔH > 0, ΔS < 0 d) ΔH < 0, ΔS < 0

CHOOSE THE CORRECT ANSWER 34. Change in Gibb’s free energy is given by a) ΔG = ΔH + TΔS b) ΔG = ΔH – TΔS c) ΔG = ΔH × TΔS d) None of the above

CHOOSE THE CORRECT ANSWER 35. For the reaction 2Cl (g) → Cl 2(g) , the signs of ΔH and ΔS respectively are a) +, – b) +, + c) –, – d) –, +

CHOOSE THE CORRECT ANSWER 36. State of chemical equilibrium is: a) dynamic b) stationery c) none d) both

CHOOSE THE CORRECT ANSWER 37. If the equilibrium constants of the following reactions are 2A B is K 1 and B 2A is K 2 , then a) K 1 = 2K 2 b) K 1 = 1/K 2 c) K 2 = (K 1 ) 2 d) K 1 = 1/K 2 2

CHOOSE THE CORRECT ANSWER 38. In the reversible reaction 2HI H 2 + I 2 , K p is a) greater than K c b) less than K c c) Equal to K c d) Zero

CHOOSE THE CORRECT ANSWER 39. In the equilibrium N2 + 3H2 2NH3, the maximum yield of ammonia will be obtained with the process having a) low pressure and high temperature b) low pressure and low temperature c) high temperature and high pressure d) high pressure and low temperature

CHOOSE THE CORRECT ANSWER 40. For the homogeneous gas reaction at 600 K 4NH 3 (g) + 5O 2 (g) 4NO(g) + 6H 2 O(g) the equilibrium constant Kc has the unit a) (mol dm -3 ) -1 b) (mol dm -3 ) c) (mol dm -3 ) 10 d) (mol dm -3 ) -9

CHOOSE THE CORRECT ANSWER 41. Two moles of ammonia gas are introduced into a previously evacuated 1.0 dm 3 vessel in which it partially dissociates at high temperature. At quilibrium 1.0 mole of ammonia remains. The equilibrium constant K c for the dissociation is a) 27/16 (mole dm -3 ) 2 b) 27/8 (mole dm -3 ) 2 c) 27/4 (mole dm -3 ) 2 d) None of these

CHOOSE THE CORRECT ANSWER 42. An equilibrium reaction is endothermic if K 1 and K 2 are the equilibrium constants at T 1 and T 2 temperatures respectively and if T 2 is greater than T 1 then a) K 1 is less than K 2 b) K 1 is greater than K 2 c) K 1 is equal to K 2 d) None

CHOOSE THE CORRECT ANSWER 43. Hydrolysis of an ester by dilute HCl is an example for (a) second order reaction (b) zero order reaction (c) pseudo first order reaction (d) first order reaction

CHOOSE THE CORRECT ANSWER 44. The unit of zero order rate constant is (a) litre mol –1 sec –1 (b) mol litre –1 sec –1 (c) sec –1 (d) litre 2 sec –1

CHOOSE THE CORRECT ANSWER 45. The excess energy which a molecule must posses to become active is known as (a) kinetic energy (b) threshold energy (c) potential energy (d) activation energy

CHOOSE THE CORRECT ANSWER 46. Arrhenius equation is (a) k = Ae

–1/RT (b) k = Ae –RT/Ea (c) k = Ae –Ea/RT (d) k = Ae Ea/RT

CHOOSE THE CORRECT ANSWER 47. The term A in Arrhenius equation is called as (a) Probability factor (b) Activation of energy (c) Collision factor (d) Frequency factor

CHOOSE THE CORRECT ANSWER 48. The sum of the powers of the concentration terms that occur in the rate equation is called (a) molecularity (b) order (c) rate (d) rate constant

CHOOSE THE CORRECT ANSWER 49. Reactions in which the reacting molecules react in more than one way yielding different set of products are called (a) consecutive reactions (b) parallel reactions (c) opposing reactions (d) chain reactions

CHOOSE THE CORRECT ANSWER 50. The half life period of a first order reaction is 10 minutes. Then its rate constant is (a) 6.93 × 10 2 min –1 (b) 0.693 × 10 –2 min –1 (c) 6.932 × 10 –2 min –1 (d) 69.3 × 10 –1 min –1

CHOOSE THE CORRECT ANSWER 51. For a reaction : aA  bB, the rate of reaction is doubled when the concentration of A is increased by four times. The rate of reaction is equal to (a) k [A] a (b) k [A] ½ (c) k [A] 1/a (d) k [A]

CHOOSE THE CORRECT ANSWER 2

N O

5  54

NO

2 

O

2 ,

d

[

N

2

O

5 ]

dt



k

1 [

N

2

O

5 ] 2

d

[

NO

2 ]

dt



k

2 [

N

2

O

5 ]

and d

[

O

2

dt

] 

k

3 [

N

2

O

5 ] 2 the relation between k1, k2 and k3 is (a) 2k 1 = 4k 2 = k 3 (b) k 1 = k 2 = k 3 (c) 2k 1 = k 2 = 4k 3 (d) 2k 1 = k 2 = k 3

CHOOSE THE CORRECT ANSWER 53. For a reaction, E a = 0 and k = 4.2 × 10 5 sec –1 at 300K, the value of k at 310K will be (a) 4.2 × 10 5 sec –1 (b) 8.4 × 10 5 sec –1 (c) 8.4 × 10 5 sec –1 (d) unpredictable

CHOOSE THE CORRECT ANSWER 54. The migration of colloidal particles under the influence of an electric field is known as (a) electroosmosis (b) cataphoresis (c) electrodialysis (d) electrophoresis

CHOOSE THE CORRECT ANSWER 55. Which one is the correct factor that explains the increase of rate of reaction by a catalyst (a) shape selectivity (b) particle size (c) increase of free energy (d) lowering of activation energy

CHOOSE THE CORRECT ANSWER 56. Fog is a colloidal solution of (a) gas in liquid (b) liquid in gas (c) gas in solid (d) solid in gas.

CHOOSE THE CORRECT ANSWER 57. The phenomenon of Tyndall’s effect is not observed in (a) emulsion (b) colloidal solution (c) true solution (d) None

CHOOSE THE CORRECT ANSWER 58. The Tyndall’s effect associated with colloidal particles is due to (a) presence of charge (b) scattering of light (c) absorption of light (d) reflection of light

CHOOSE THE CORRECT ANSWER 59. In case of physical adsorption, there is desorption when (a) temperature increases (b) temperature decreases (c) pressure increases (d) concentration increases

CHOOSE THE CORRECT ANSWER 60. Colloidal medicines are more effective because (a) they are clean (b) they are easy to prepare (c) the germs more towards, them (d) they are easily assimilated and adsorbed

CHOOSE THE CORRECT ANSWER 61. Oil soluble dye is mixed with emulsion and emulsion remains colourless then, the emulsion is (a) O/W (b) W/O (c) O/O (d) W/W

CHOOSE THE CORRECT ANSWER 62. For selective hydrogenation of alkynes into alkene the catalyst used is (a) Ni at 250°C (b) Pt at 25°C (c) Pd, partially inactivated by quinoline (d) Raney nickel

CHOOSE THE CORRECT ANSWER 63. For chemisorption, which is wrong (a) irreversible (b) it requires activation energy (c) it forms multimolecular layers on adsorbate (d) surface compounds are formed

CHOOSE THE CORRECT ANSWER 64. An emulsion is a colloidal solution of (a) two solids (b) two liquids (c) two gases (d) one solid and one liquid

CHOOSE THE CORRECT ANSWER 65. Colloids are purified by (a) precipitation (b) coagulation (c) dialysis (d) filtration

CHOOSE THE CORRECT ANSWER 66. The process in which chemical change occurs on passing electricity is termed as ...............

(a) neutralisation (b) hydrolysis (c) electrolysis (d) ionisation

CHOOSE THE CORRECT ANSWER 67. The laws of electrolysis were enunciated first by .......

(a) Dalton (b) Faraday (c) Kekule (d) Avogadro

CHOOSE THE CORRECT ANSWER 68. When one coulomb of electricity is passed through an electrolytic solution, the mass deposited on the electrode is equal to ...............

(a) equivalent weight (b) molecular weight (c) electrochemical equivalent (d) one gram

CHOOSE THE CORRECT ANSWER 69. Faraday’s laws of electrolysis are related to ...............

(a) atomic number of the cation (b) atomic number of the anion (c) equivalent weight of the electrolyte (d) speed of the cation

CHOOSE THE CORRECT ANSWER 70. The specific conductance of a 0.01 M solution of KCl is 0.0014 ohm -1 cm -1 at 25  C. Its equivalent conductance is ...............

(a) 14 ohm –1 cm 2 eq –1 (b) 140 ohm –1 cm 2 eq –1 (c) 1.4 ohm –1 cm 2 eq –1 (d) 0.14 ohm –1 cm 2 eq –1

CHOOSE THE CORRECT ANSWER 71. The equivalent conductivity of CH 3 COOH at 25  C is 80 ohm -1 cm 2 eq -1 and at infinite dilution 400 ohm -1 cm 2 eq -1 . The degree of dissociation of CH 3 COOH is ...............

(a) 1 (b) 0.2 (c) 0.1 (d) 0.3

CHOOSE THE CORRECT ANSWER 72. When sodium acetate is added to acetic acid, the degree of ionisation of acetic acid ...............

(a) increases (b) decreases (c) does not change (d) becomes zero

CHOOSE THE CORRECT ANSWER 73. NH 4 OH is a weak base because ...............

(a) it has low vapour pressure (b) it is only partially ionised (c) it is completely ionised (d) it has low density

CHOOSE THE CORRECT ANSWER 74. Which one of the following formulae represents Ostwald’s dilution law for a binary electrolyte whose degree of dissociation is a and concentration C.

(a)

K

   

C

(b)

K

  2

C

1   (c)

K

  

C

 2 (d)

K

  2

C

 

C

CHOOSE THE CORRECT ANSWER 75. Ostwald’s dilution law is applicable in the case of the solution of ...............

(a) CH 3 COOH (b) NaCl (c) NaOH (d) H 2 SO 4

CHOOSE THE CORRECT ANSWER 76. Which one of the following relationship is correct ? (a)

pH

 [

H

1  ] (b) Ph = log 10 [H + ] (c) log 10 pH = [H + ] (d)

pH

 log 10 1 [

H

 ]

CHOOSE THE CORRECT ANSWER 77. When 10 –6 mole of a monobasic strong acid is dissolved in one litre of solvent, the pH of the solution is ...........

(a) 6 (b) 7 (c) less than 6 (d) more than 7

CHOOSE THE CORRECT ANSWER 78. When pH of a solution is 2, the hydrogen ion concentration in moles litre -1 is .............

(a) 1 × 10 –12 (b) 1 × 10 –2 (c) 1 × 10 –7 (d) 1 × 10 –4

CHOOSE THE CORRECT ANSWER 79. The pH of a solution containing 0.1 N NaOH solution is ..........

(a) 1 (b) 10 –1 (c) 13 (d) 10 –13

CHOOSE THE CORRECT ANSWER 80. A solution which is resistant to changes of pH on addition of small amounts of an acid or a base is known as .............

(a) buffer solution (b) true solution (c) isohydric solution (d) ideal solution

CHOOSE THE CORRECT ANSWER 81. The hydrogen ion concentration of a buffer solution consisting of a weak acid and its salt is given by ............. (a) [

H

 ] 

K a

[

Acid

] [

Salt

] (b) [H + ] = K a [Salt] (c) [H + ] = K a [Acid] (d) [

H

 ]  [

Salt

]

K a

[

Acid

]

CHOOSE THE CORRECT ANSWER 82. Indicators used in acid-base titrations are ...........

(a) strong organic acids (b) strong organic bases (c) weak organic acids or weak organic bases (d) non-electrolysis

CHOOSE THE CORRECT ANSWER 83. For the titration between oxalic acid and sodium hydroxide, the indicator used in ...........

(a) potassium permanganate (b) phenolphthalein (c) litmus (d) methyl orange

CHOOSE THE CORRECT ANSWER 84. The potential of a single electrode is a half cell is called the (a) Reduction potential (b) Half-wave potential (c) Single electrode potential (d) cell potential

CHOOSE THE CORRECT ANSWER 85. The relationship between free energy change and e.m.f. of a cell is (a)  G = –nFE (b)  H = –nFE (c)  E = nFG (d)  F = nEG

CHOOSE THE CORRECT ANSWER 86. The feasibility of a redox reaction can be predicted with the help of (a) Electronegativity (b) Electrochemical series (c) Electron affinity (d) Equivalent conductance

CHOOSE THE CORRECT ANSWER 87. The metals near the bottom of the electrochemical series are (a) strong reducing agents (b) strong oxidising agents (c) weak reducing agents (d) weak oxidising agents

CHOOSE THE CORRECT ANSWER 88. The emf of a cell with 1 M solutions of reactants and products in solution at 25  C is called (a) Half cell potential (b) Standard emf (c) Single electrode potential (d) Redox potential

CHOOSE THE CORRECT ANSWER 89. The relationship between equilibrium constant and standard emf of a cell is (a) E o = 0.0591 log K (b) 0.0591 E o = log K (c) nE o = 0.0951 log K (d) nE o = 0.0591 log K

CHOOSE THE CORRECT ANSWER 90. Identify chiral molecule among the following : (a) isopropyl alcohol (b) isobutyl alcohol (c) 2-pentanol (d) 1-bromo-3-butene

CHOOSE THE CORRECT ANSWER 91. Which among the following is not having an asymmetric carbon atom ?

(a) 2-chloro butane (b) 2-bromo-3-butene (c) 2-hydroxy propanal (d) isobutyric acid

CHOOSE THE CORRECT ANSWER 92. Which among the following can be a chiral center ?

(a) C + of a cabocation (b) carbon of a radical (c) an sp 2 carbon (d) an sp 3 carbon