PAPER – I

 

 

61. 17g of hydrogen peroxide is present in 1120 ml of solution. This solution is called

(A) 5 volume solution                                      (B) 10 volume solution

(C) 15 volume solution                                    (D) 16 volume solution

 

62. The density of a gas at 27°C and 1 atm is d. Pressure remaining constant, at which of the following temperature will its density become 0.75d.

(A) 20°C                                                          (B) 30°C

(C) 36°C                                                          (D) 127°C

 

63. Radioactivity of radioactive element remains 1/10 of the original radioactivity after 2.303 seconds. The half life period (in seconds) is

(A) 2.303                                                         (B) 0.693

(C) 0.2303                                                       (D) 0.0693

 

64. Assuming complete dissociation predict which of the following will have pH = 12.

(A) 500 ml 0.005 M NaOH                             (B) 1000 ml 0.005 M Ca(OH)₂

(C) 100 ml 0.05 M Ca(OH)₂                           (D) 50 ml 0.05 M NaOH

 

65. The percentage of metal in its oxide is 60. The percentage of bromine in metal bromide (oxidation state of metal remains the same) will be

(A) ~ 87                                                           (B) ~ 97

(C) ~ 77                                                           (D) ~ 80

 

66. Which of the following will be most reactive towards the nucleophilic substitution.

(A)		(B)
(C)		(D)

 

67. 50g of CaCO₃ when treated with 60 ml of 20 N HCl at 300 K and 4 atm produces

(A) 22 g CO₂                                                   (B) 44g CO₂

(C) 11g CO₂                                                    (D) 88 g CO₂

 

68. A certain weak acid has a dissociation constant of 10^–5. The equilibrium constant for its reaction with a strong base is

(A) 10^–9                                                           (B) 10⁺¹⁴

(C) 10⁹                                                            (D) 10^–5

 

69. The species with maximum magnetic moment is

(A) K₄[Ni(CN)₆]                                               (B) K₄[Fe(CN)₆]

(C) K₃[Co(CN)₆]                                              (D) [Cu(NH₃)₄]SO₄

 

70. Acetophenone on reaction with p -nitroperbenzoic acid gives

(A) phenyl propionate                                     (B) phenyl acetate

(C) methyl benzoate                                       (D) benzophenone

71.
(A)			(B)
(C)			(D)

 

72.

(A) PhCOOH, CH₃NH₂                                  (B) CH₃COOH, PhNH₂

(C) 2PhCOOH                                                (D) None of these

 

73. L₁ and L₂ are the lattice energies of NaF and CsF respectively and IC₁ and IC₂ are the ionic characters of NaF and CsF respectively. Then

(A) IC₁ > IC₂ & L₁ > L₂                                    (B) IC₁ < IC₂ and L₂ > L₁

(C) IC₁ > IC₂ & L₂ > L₁                                    (D) IC₁ < IC₂ & L₂ < L₁

 

74. A compound of vanadium has a magnetic moment of Ö8 B.M. Hence the vanadium ion is

(A) V²⁺                                                             (B) V⁺

(C) V⁴⁺                                                            (D) V³⁺

 

75. In which of the following solutions AgBr will be maximum soluble?

(A) 10^–3 M NaBr                                              (B) 10^–3M NH₄OH

(C) Pure water                                                (D) 10^–3 M HBr

 

76. Copper can be deposited from acidified CuSO₄ and alkaline CuCN. If 5 amp current is passed for 5 min through both the solutions separately, which of the following is correct.

(A) The amount of Cu deposited from acidic CuSO₄ solution will be higher.

(B) The amount of Cu deposited from alkaline CuCN solution will be higher.

(C) The same amount of Cu will be deposited in both the cases.

(D) It cannot be predicted.

 

77. The chemical reaction 2O₃ ¾® 3O₂ proceeds as follows

O₃  O₂ + O (fast)

O + O₃ ¾® 2O₂ (slow)

The rate law expression for 2O₃ ¾® 3O₂ reaction  should be [K is rate constant]

(A) Rate = K[O₃]²                                            (B) Rate = K[O₃]²[O₂]^–1

(C) Rate = K[O₃][O₂]                                      (D) None of these

 

78. When CO₂ dissolves in water the following equilibrium is established;

CO₂ + 2H₂O  H₃O⁺ + HCO₃^–

For this equilibrium K_c is 3.8 ´ 10^–6 and pH = 6 at the same temperature. So at that temperature is

(A) 3.8 ´ 10^–12                                                 (B) 3.8

(C) 6.7 ´ 10^–2                                                  (D) 13.4

 

79. Hydrated proton can exist in water as

(A) H₃O⁺                                                         (B) H_­5O₂⁺

(C) H₉O₄⁺                                                        (D) All of these

 

80. What will be the product of the following reaction

CH₃—CH=CH₂ + IN₃ ¾¾® ?

(A)		(B)
(C)		(D)	None

 

81. Dehydrohalogenation of the following in increasing order

 

(A) I < II < III                                                    (B) III < II < I

(C) I = II < III                                                    (D) III < I = II

 

82.	in the above reaction A and B are
(A)			(B)
(C)			(D)	Formation of A and B is not possible.

 

83. An organic compound of molecular formula C₄H₆(A), forms precipitate with ammonical cuprous chloride. A has an isomer B, one mole of which reacts with one mole of Br₂ to form 1,4 – dibromo-2-butene. A and B are

(A) CH₃—CH₂—C º CH and CH₂ = CH—CH=CH₂

(B) CH₃—CºC—CH₃ and CH₃—CH=C=CH₂

(C)
(D)

 

84. Coupling with diazonium salts of the following takes place in the order of

 

(A) IV < II < III < I                                             (B)  IV < III < II < I

(C)  II < IV < I < III                                           (D) I < II < III < IV

 

85. The product X of the following reaction is

 

(A)		(B)
(C)		(D)	I – CH2 – CH2 – I

 

86. What will be the final product ‘B’ of the following reaction?

A  B

(A)		(B)	C6H5 – CH = CH – COCH3
(C)	C6H5CH = CH – COONa	(D)	C6H5COOH

 

87. Find the final product Z of the following reaction

 

(A)		(B)
(C)		(D)

 

88.

 

(A) I and II                                                       (B) I and IV

(C)  I, II and III                                                 (D) All the four

 

89. Which one is the most stable complex, if the equilibrium constants are

(A) 1.0 ´ 10^–12                                                 (B) 1.0 ´ 10^–10

(C)  1.0 ´ 10^–8                                                 (D) 1.0 ´ 10^–6

 

90. The basic character of hydrides of the VB group elements decreases in the order

(A) NH₃ > PH₃> AsH₃ > SbH₃                        (B) SbH₃ > PH₃ > AsH₃ > NH₃

(C)  NH₃  > SbH₃ > PH₃ > AsH₃                     (D) SbH₃ > AsH₃ > PH₃ > NH₃

 

 

 

Answers

 

61. A                                         

.                 62.       D                                          63.       B                                          64.       B        

65. A                                          66.       D                                          67.       A        
66. 68. C                                                 D                                          70.       B        
67. C                                          72.       A                                          73.       D        
68. D                                          75.       B                                          76.       B        
69. B                                          78.       B                                          79.       D        
70. B                                          81.       B                                          82.       C        
71. 83. A                                          84.       A                                                 C        
72. C                                          87.       D                                          88.       B        
73. A                                          90.       A

 

Hints & Solutions

 

61. Weight of H₂O₂ in 1 ml =

Moles of H₂O₂ in 1 ml =

Moles of O₂ liberated =

Volume of O₂ liberated =  = 5 ml

 

62. PM = dRT or d µ

 

\T₂ = 127°C

 

Putting the values we get

t_1/2 = 0.693

 

64. pH = 12, pOH = 2 Þ [OH^–] = 10^–2 M

 

65. % of M in M_xO_y = = 60 \ xM = 24y

% M in M_xBr_2y =  » 13

\ % of bromine in M_xBr_2y @ 87

 

66. is the best leaving group as it is the weakest base

 

67. Equivalents of CaCO­₃ = = 1

Equivalent of HCl =  = 1.2

\ Equivalent of CO₂ = 1, moles of CO₂ = 0.5 (n-factor = 2)

\ mass of CO₂ = 22g

 

Ka

68. HA + OH^–  A^– + H₂O

Kh

K_h =  = 10^–9

K_a = K_h^–1 = 10⁹

 

69. Because it has maximum no. of unpaired electrons.

 

70.

 

71.

 

74. We know magnetic moment of B.M. V³⁺ is ‘d²’ system. So it’s magnetic moment is Ö8 B.M.

 

75. Solubility of AgBr is maximum in NH₄OH due to soluble complex [Ag(NH₃)₂]Br formation

 

76. Cu²⁺ + 2e ¾® Cu (from CuSO₄)

Cu⁺ + e ¾® Cu (from CuCN)

So if same amount of charge is passed through both the solution alkaline CuCN will deposit more Cu.

 

77. The slow r.d.s gives rate = K[O][O₃]

and K_c =

or [O] =

from this Rate =  = [K¢ is overall rate constant]

 

78. K_c

[H₃O⁺] = 10^–6 Since pH = 6

or  = 3.8

 

79. H⁺ + H₂O ¾® H₃O⁺

H⁺ + 2H₂O ¾® H₅O₂⁺

H⁺ + 4H₂O ¾® H₉O₄⁺

H₅O₂⁺ and H₉O₄⁺can exist in solid state also

 

80. IN₃ I⁺ +

 

81. 1° < 2° < 3°

 

82. LiAlH₄ reduces keto, aldehyde and even cyclic ester, NaBH₄ also reduces keto and aldehyde but not ester

 

83. A has acidic H hence CH₃CH₂Cº CH

B reacts with one mole of Br₂ by 1,4 addition hence CH₂=CH—CH=CH₂

 

86. C₆H₅CHO+CH₃COCH₃ C₆H₅—CH=CH—COCH₃

 

C₆H₅CH = CH – COCH₃ + NaCl + CHCl₃

 

87.

 

89. Stability constant of a complex ion is the reciprocal of its equilibrium / dissociation constant. Smaller the value of equilibrium constant, greater will be the stability of that complex.

 

90. The basic character of hydrides decreases down the group.