Chemistry 13_Objective_Phase VI

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  1. If E0 (Fe3+/Fe) = – 0.036 V & E0‑(Fe2+/Fe) = – 0.439 V, the value of E0 (Fe3+, Fe2+/Pt) is

(A) – 0.475 V                                                   (B) 0.403 V

(C) 0.77V                                                         (d)  0.986 V

 

  1. The standard reduction potential of 2H2O + 2e ¾® H2 + 2OH at 298 K is

(A) 0.828 V                                                      (B) – 0.828 V

(C) 0.414 V                                                      (D) – 0.414V

 

  1. If E0 (Fe2+/Fe) = – 0.44V & E0(Pb2+/Pb) = – 0.13V, then adding powdered Pb & Fe to a solution containing 1 M in each of Pb2+ & Fe2+ ions would result into the formation of

(A) more of Pb & Fe2+ ions                             (B) more of Fe & Pb2+ions

(C) more of Fe & Pb                                       (D) more of Fe2+ & Pb2+ ions

 

  1. In acidic medium Cr2O72– is converted to Cr3+ when it acts as an oxidising agent. The quantity of electricity required to reduce 0.05 mole of Cr2O72– would be

(A) 0.05 F                                                        (B) 0.1 F

(C) 0.2 F                                                          (D) 0.3 F

 

  1. The edge length of unit cell of sodium chloride is 564 pm. If the size of Cl ion is 181 pm, the size of Na+ ion would be

(A) 383 pm                                                      (B) 282 pm

(C) 101 pm                                                      (D) 202 pm

 

  1. The co-ordination number of metal crystallizing in hexagonal close-packed (hcp) structure is

(A) 12                                                              (B) 10

(C) 8                                                                (D) 6

 

  1. Which of the following statements is correct?

(A) The co-ordination number of each type of ion in CsCl crystal is 8

(B) A metal that crystallizes in bcc structure has a co-ordination number of 12

(C) The length of the unit cell in NaCl is 552 pm ( = 95 pm, = 181 pm)

(D) The packing fraction for bcc structure is 0.52

 

  1. Copper displaces which of the metal from the salt solutions?

(A) AgNO3                                                      (B) ZnSO4

(C) FeSO­4                                                       (D) All of the above

 

  1. Of the following metals, which one cannot be obtained by electrolysis of the aqueous solution of its salt is

(A) Ag                                                              (B) Mg

(C) Cu                                                             (D) Al

 

  1. How many electrons are there in one coulomb?

(A) 6.023 ´ 1023                                              (B) 96500

(C) 1.6 ´ 10–19                                                 (D) 6.24 ´ 1018

 

  1. How much current is necessary to produce hydrogen gas at a rate of 1200 cc per second at NTP conditions?

(A) 96500 ampere                                           (B) 48250 ampere

(C) 8.616 ampere                                            (D) 14800 ampere

 

  1. The e.m.f. of half cell PtH­2 (2 atm) | HCl (a = 0.02) & E0OP= 0 V is

(A) + 0.19 volt                                                 (B) + 0.403 volt

(C) – 0.409 volt                                               (D) – 0.109 volt

 

  1. Given & . Then

(A) Ag+ can be reduced by H2                        (B) Ag can oxidise H2(g) to H+

(C) Zn2+ can be reduced by H2                      (D) Ag can reduce Zn2+

 

  1. The crystalline compound AxBy is characterised by a body-centered cell. The compound has the formula.

(A) AB                                                             (B) A4B

(C) A8B                                                            (D) AB4

  1. A solution of CuSO4 is electrolysed using platinum inert electrodes. Due to electrolysis, the colour changes from blue to _________ and pH of the solution ________.

(A) red, unaltered                                            (B) colourless, increases

(C) blue, decreases                                         (D) colourless, decreases,

 

  1. A solution of sodium sulphate is electrolysed using inert electrodes and the gases evolved are stored in a container. What is the mole fraction of gas in container which have higher concentration.

(A)                                                               (B) 0.33

(C) 2/3                                                             (D) 4/5

(E) None

 

  1. The reduction potential of hydrogen half cell will be negative if

(A)  = 1 atm and [H+] = 1 M                      (B)  = 1 atm and [H+] = 2 M

(C) = 1.5 atm and [H+] = 1 M                    (D)  = 1.2 atm and [H+] = 1.2 M

 

  1. A current of 1 ampere is passed through CuSO4 solution for 965 second. What mass of Cu is deposited at cathode?

(A) 0.3175 gm                                                 (B) 0.635 gm

(C) 0.15875 gm                                               (D) 0.238 gm

 

  1. 1 faraday of electricity will deposit 108 gm of silver. What is electro-chemical equivalent of the substance?

(A) 1.119 ´ 10–3                                              (B) 2.238 ´ 10–3

(C) 0.108                                                         (D) 1.08

 

  1. The mass of unit cell of CsCl corresponds to

(A) 1Cs+ and 1Cl                                     (B) 1Cs+ and 6Cl

(C) 4Cs+ and 4Cl                                     (D) 8Cs+ and 1Cl

 

  1. Which of the following is a non-crystalline solid

(A) CsCl                                                    (B) NaCl

(C) CaF2                                                    (D) Glass

 

  1. Crystals of covalent compounds always have

(A) Atoms as their structural unit

(B) Molecules as their structural units

(C) Ions held together by electrostatic force

(D) High Melting point

 

  1. Tetragonal crystal system has the following unit cell dimensions

(A) a = b = c and a = b = g = 90°

(B) a = b ¹ c and a = b = g = 90°

(C) a = b ¹ c and a = b = g ¹ 90°

(D) a = b ¹ c and a = b = 90°; g = 120°

 

  1. The 8:8 type of packing is present in

(A) NaCl                                                    (B) KCl

(C) CsCl                                                    (D) MgF2

  1. Given

C + 2S ¾® CS2 DHf0 = + 117.0 kJ mol–1

C + O2  ¾® CO2; DH­f0 = –393 kJ mol–1

S + O2  ¾® SO2; DHf0 = – 297 kJ mol–1

The heat of combustion of

CS2 + 3O2  ¾® CO2 + 2SO2 is

(A) – 807 kJ mol–1                                          (B) – 1104 kJ mol–1

(C) + 1104 kJ mol–1                                        (D) + 807 kJ mol–1

 

  1. If C(s) + O2(g) ¾® CO2(g); DH = X

and

CO(g) + O2 (g) ¾® CO2(g) DH = Y

Then the heat of formation of CO is

(A) X + Y                                                         (B) X – Y

(C) Y – X                                                         (D) X . Y

 

  1. Heat of neutralization is highest in the reaction between

(A) HNO3 – NH4OH                                        (B) HCl – NaOH

(C) NH4OH – CH3COOH                               (D) NaOH – CH­3COOH

 

  1. The energy change of reaction

C2H6(g) ¾® 2C(g) + 6H(g) is X kJ

The bond energy of C – H bond is

(A) X/6 kJ                                                        (B) X/3 kJ

(C) X kJ                                                           (D) indeterminate

 

  1. Which of the following describes the criterion of spontaneity

(A) DHT, p > 0                                                    (B) DSTotal > 0

(C) DG­T, P>0                                                     (D) All of these

 

  1. For an endothermic reaction where DH represents the enthalpy of the reaction in kJ/mole, the minimum value for the energy of activation will be

(A) less than DH                                              (B) zero

(C) more than DH                                      (D) equal to DH

Answers

 

  1. C 62.       B
  2. A 64.       D
  3. C 66.       A
  4. A 68.       A
  5. B 70.       D
  6. A 72.       A
  7. A 74.       A
  8. D 76.       C
  9. C 78.       A
  10. A 80.       A
  11. D 82.       A
  12. B 84.       C
  13. B 86.       B
  14. B 88.       A
  15. B 90.       C