Your Cart

Chemistry 13_Objective_Paper Phase I to VI

Loader Loading...
EAD Logo Taking too long?

Reload Reload document
| Open Open in new tab

PAPER – I

 

  1. A radioactive isotope having a half-life of 3 days was received after 12 days. It was found that there were 3g of the isotope in the container. The initial weight of the isotope when packed was

(A) 12g                                                            (B) 24g

(C) 36g                                                            (D) 48g

 

  1. Which one has peroxide linkage?

(A)                                                        (B)

(C)                                                        (D)

 

  1. Among the following compounds the one that is polar and has the central atom with sp3 hybridisation is

(A) H2CO3                                                       (B) SiF4

(C) BF3                                                            (D) HClO2

 

  1. A solution contains Na2CO3 and NaHCO3. 10 ml of the solution required 2.5 ml of 0.1 M H2SO4 for neutralisation using phenolphthalein as indicator. Methyl orange is then added when a further 2.5 ml of 0.2 M H2SO4 was required. The amount of Na2CO3 and NaHCO3 in 1 litre of the solution is

(A) 5.3 g and 4.2 g                                          (B) 3.3 g and 6.2 g

(C) 4.2 g and 5.3 g                                          (D) 6.2 g and 3.3 g

 

  1. The values of observed and calculated molecular weights of silver nitrate are 92.64 and 170 respectively. The degree of dissociation of silver nitrate is

(A) 60%                                                           (B) 83.5%

(C) 46.7%                                                        (D) 60.23%

 

  1. 10 ml of a strong acid solution of pH = 2 are mixed with 990 ml of another strong acid solution of pH = 4. The pH of the resulting solution will be:

(A) 4.002                                                         (B) 4.8

(C) 4.2                                                             (D) 3.72

 

  1. The pH of pure water at 25°C and 35°C are 7 and 6 respectively. The heat of formation of water from H+ and OH are

(A) 84.55 kcal mol–1                                       (B) – 84.55 kcal mole–1

(C) 74.55 kcal mol–1                                       (D) – 74.55 kcal mole–1

 

  1. Which reaction is endothermic in nature?

(A) Fe + S ¾® FeS                                       (B) NaOH + HCl ¾® NaCl + H2O

(C) CaCO3 ¾® CaO + CO2                         (D) CH4 + 2O2 ¾® CO2 + 2H­2O

 

  1. In a face centred cubic arrangement of A and B atoms whose A atoms are at the corner of the unit cell and B atoms are at the face centres. One of the A atom is missing from one corner in unit cell. The simplest formula of the compound is:

(A) A7B3                                                          (B) AB3

(C) A7B24                                                         (D) A7/8B3

 

  1. Which pair of elements is chemically most similar?

(A) Na, Al                                                        (B) Cu, S

(C) Ti, Zr                                                          (D) Zr, Hf

 

  1. An inorganic compound first melts then resolidifes and then liberates a gas. It may be:

(A) KClO3                                                        (B) KMnO4

(C) Al2O3                                                         (D) BeCl2

  1. Which is maximum hydrated

(A) NaCl                                                          (B) MgCl­2

(C) AlCl3                                                          (D) BeCl­2

 

  1. Between p-nitrophenol and salicyaldehyde, solubility in base is

(A) Almost nil in both cases                            (B) Higher in p-nitrophenol

(C) Higher for salicylaldehyde                        (D) Equal in nature

 

  1. An organic compound C­3H6O does not give a precipitate with 2, 4-dinitrophenylhydrazine reagent and does not react with sodium metal. It could be

(A) CH3 – CH2 – CHO                                    (B) CH3 – COCH3

(C) CH2 = CH – CH2OH                                 (D) CH2 = CH – OCH3

 

  1. The reagent which can be used to distinguish acetophenone from Benzophenone is:

(A) 2, 4-dinitrophenylhydrazine                       (B) aqueous NaHSO3

(C) Benedict’s solution                                    (D) I­2 and NaOH

 

  1. The bond length is O2+, O2, O2 and O22– follows the order

(A) O22– > O2 > O2 > O2+                              (B) O2+ > O2 > O2 > O22–

(C) O2 > O2 > O22– > O2+                              (D) O2 > O22– > O2+ > O2

 

  1. CuSO4 solution reacts with KCN to form a complex

(A) Cu(CN)2                                                    (B) Cu(CN)

(C) K2[Cu(CN)4]                                              (D) K3[Cu(CN)4]

 

  1. The first ionisation potential of aluminium is less than that of magnesium, because

(A) atomic size of Al < Mg                              (B) Atomic size of Al > Mg

(C)  Al has one electron in p-orbital                (D) none

 

  1. Solubility of alkaline earth metal hydroxides increases from, Be(OH)2 to Ba(OH)2 because

(A) Lattice energy > Hydration energy

(B) Hydration energy > Lattice energy

(C)  Lattice energy is equal to hydration energy

(D) none of these

 

  1. Which statement is correct with respect to the property of the elements with increase in atomic number in the carbon family.

(A) Their metallic character decreases          (B) The stability of +2 oxidation state increases

(C)  Their ionisation energy increases            (D) Their atomic size decreases

 

  1. The magnetic behaviour of complexes K4[Fe(CN)6] and K3[Fe(CN)6].

(A) Diamagnetic , ferromagnetic                    (B) Paramagnetic, diamagnetic

(C)  Diamagentic, paramagnetic                    (D) none of these

 

  1. Which of the interhalogen compound does not exist?

(A) BrF5                                                           (B) ClF3

(C)  FCl3                                                          (D) ClF

 

83.
            (A) (B)
            (C) (D)

 

84.
            (A) (B)
            (C) (D)

 

85.
            (A) (B)
            (C) (D) None of these

 

86.
            (A) (B)
            (C) (D)

 

  1. p-benzoquinone reacts with excess 1, 3-butadiene. The product is
            (A) (B)
            (C) (D) None

 

  1. A Nitration product. The rate will be maximum, when A is
            (A) (B)
            (C) (D)

 

  1. CO(OEt)2 ultimate product would be

(A) Ketone                                                       (B) Aldehyde

(C) Tertiary alcohol                                         (D) None

 

  1. Which of the following compound doesn’t undergo decarboxylation on heating?
            (A) (B)  
            (C) (D)

 

Answers

 

  1. D                                         

.                 62.       A                                          63.       D                                          64.       A        

  1. B                                          66.       D                                          67.       B        
  2. 68. C                                                 C                                          70.       D        
  3. A                                          72.       D                                          73.       B        
  4. D                                          75.       D                                          76.       A        
  5. D                                          78.       C                                          79.       B        
  6. B                                          81.       C                                          82.       C        
  7. 83. A                                          84.       A                                                 B        
  8. D                                          87.       D                                          88.       D        
  9. C                                          90.       B

 

Hints & Solutions

 

  1. n = = 4

\ N0 = N ´ 2n = 3 ´ 24 = 48g

 

62.

 

  1. Carbon in H2CO3 has sp2 hybridsation and non-polar. BF3has sp2 hybridisation but non-polar. SiF4 and HClO2 has sp3hybridisation but HClO2 is polar.

 

  1. For phenolphthalein

Meq. of Na2CO3 = 2.5  ´ 0.1 ´ 2 = 0.5

For methyl orange

Meq. of Na2CO3 + Meq. of NaHCO3 = 2.5 ´ 0.2 ´ 2 = 1.0

\ Meq. of NaHCO3 = 0.5 and Meq. of Na­2CO3 = 1.0

= 0.5 1000 = 1

W = 0.042 g in 10 mL \ W = 0.053 g in 10 mL

\ W = 4.2 g in 1 litre = 5.3 g in 1 litre

 

  1. i for AgNO3 = = 1 + a

a =  – 1 = 0.835 = 83.5%

 

  1. [H+] after mixing = = 1.9 ´ 10–4

pH = 3.72

 

  1. At 25°C [H+] = 10–7; \ Kw = 10–14

At 35°C [H+] = 10–6; \ Kw = 10–12

Now using,

2.303 log

We get, DH = 84.55 kcal/mole

Thus H2O  H+ + OH                              DH = 84.55

\ H+ + OH  H2O                                   DH = – 84.55 kcal/mole

 

  1. Decomposition of CaCO3 is made on heating.

 

  1. No. of atoms of A from corners of unit cell =

No. of atoms of B from faces of unit cell = 3

Thus A : B : : 3 (or) 7 : 24

 

  1. Due to Lanthanide contraction.

 

  1. Smaller is the ion, more is the hydration

 

  1. Because of acidic nature

 

  1. It is neither a carbonyl compound (do not give a test with hydrazine) nor an alcohol and thus it may be ether.

 

  1. Acetophenone will show iodoform Test

                                                                                         

  1. The bond length decreases with increase in bond order in diatomic molecule A result of molecular orbital theory.

 

  1. Removal of electron from 2p shell is easier in comparison to 2s shell

 

  1. Due to inert pair effect which increases down the group

 

  1. K4[Fe(CN)6] ® Fe2+, d6 – configuration

CN strong ligand

    ¾® Diamagnetic

K3[Fe(CN)6] ¾® Fe3+, d5 configuration

 

    ¾® Paramagnetic

 

84.

 

  1. In Baeyer-Villiger oxidation, group having higher migratory aptitude migrates on oxygen.

 

87.

 

  1. Double bond at bridge head position is not possible due to strain.

 

 

 

Leave a Reply

Your email address will not be published.

X