JEE Advance - Chemistry (1991)

• 1

  Arrange of the following in :
  Arrange the following ions in order of their increasing radii:
  Li⁺, Mg²⁺, K⁺, Al³⁺

  回答

  (B)

  Al³⁺ < Mg²⁺ < Li⁺ < K⁺
• 2

  The weight of $$1 \times 10^{22}$$ molecules of CuSO₄.5H₂O is ____.

  回答

  (B)

  4.14 g
• 3

  The oxidation state of the most electronegative element in the products of the reaction. BaO₂ with dil. H₂SO₄ are

  回答

  (D)

  -2 and -1
• 4

  A 1.0 g sample of Fe₂O₃ solid of 55.2% purity is dissolved in acid and reduced by heating the solution with zinc dust. The resultant solution is cooled and made upto 100.0 ml. An aliquot of 25.0 ml of this solution requires 17.0 ml of 0.0167M solution of an oxidant for titration. Calculate the number of electrons taken by the oxidant in the reaction of the above titration.

  回答

  (D)

  6
• 5

  A solution of 0.2 g of a compound containing Cu²⁺ and $$C_2O_4^{2-}$$ ions on titration with 0.02M $$KMnO_4$$ in presence of $$H_2SO_4$$ consumes 22.6 ml. of the oxidant. The resultant solution in neutralized with Na₂CO₃, acidified with dil. acetic acid and treated with excess KI. The liberated iodine requires 11.3 ml of 0.05M Na₂S₂O₃ solution for complete reduction.
  
  Find out the molar ratio of Cu²⁺ to $$C_2O_4^{2-}$$ in the compound.Write down the balanced redox reactions involved in the above titrations.

  回答

  (B)

  1:2
• 6

  Read the following statement and explanation and answer as per the options given below:
  
  STATEMENT (S): In the titration of Na₂CO₃ with HCl using methyl orange indicator, the volume required at the equivalence point is twice that of the acid required using phenolphthalein indicator.
  
  EXPLANATION (E): Two moles of HCl are required for the complete neutralization of one mole of Na₂CO₃

  回答

  (B)

  Both S and E are true, and E is not the correct explanation of S.
• 7

  Arrange of the following in :
  Increasing order of ionic size:
  N^3-, Na⁺, F^-, O^2-, Mg²⁺

  回答

  (B)

  Mg²⁺ < Na⁺ < F^- < O^2- < N^3-
• 8

  Arrange of the following in :
  Increasing order of basic character
  MgO, SrO, K₂O, NiO, Cs₂O

  回答

  (C)

  NiO < MgO < SrO < K2O < Cs2O
• 9

  The linear structure is assumed by :

  回答

  B

  C

  D
• 10

  Arrange the following :
  
  Increasing strength of hydrogen bonding (X-H-X):
  
  O, S, F, Cl, N

  回答

  (A)

  Cl < S < N < O < F
• 11

  Calculate the volume occupied by 5.0 g of acetylene gas at 50^oC and 740 mm pressure.

  回答

  (C)

  5.23 L
• 12

  The volume strength of 1.5 N H₂O₂ solution is

  回答

  (B)

  8.4
• 13

  Write down the balanced equation for the reaction when:
  Carbon dioxide is passed through a suspension of lime stone in water.

  回答

  (A)

  CaCO3(s) + H2O(l) + CO2(g) → Ca(HCO3)2(aq)
• 14

  The hybridization of carbon atoms in C-C single bond of HC $$ \equiv $$ C - CH = CH₂ is

  回答

  (C)

  $$sp - sp^2$$
• 15

  The degree of dissociation of calcium nitrate in a dilute aqueous solution, containing 7.0 g. of the salt per 100 gm of water at 100^oC is 70%. If the vapour pressure of water at 100^oC is 760 mm, calculate the vapour pressure of the solution.

  回答

  (B)

  746.3 mm Hg
• 16

  Zinc granules are added in excess to a 500 ml. of 1.0 M nickel nitrate solution at 25^oC until the equilibrium is reached. If the standard reduction potential of Zn²⁺ | Zn and Ni²⁺ | Ni are -0.75 V and -0.24 V respectively, find out the concentration of Ni²⁺ in solution at equilibrium.

  回答

  (C)

  5.26 x 10^-18 M
• 17

  The current of 1.70 A is passed through 300.0 ml of 0.160 M solution of a ZnSO₄ for 230 sec. with a current efficiency of 90%. Find out the molarity of Zn²⁺ after the deposition of Zn. Assume the volume of the solution to remain constant during electrolysis.

  回答

  (C)

  0.154 M
• 18

  The decomposition of N₂O₅ according to the equation:
  2N₂O₅ (g) $$\to$$ 4NO₂(g) + O₂(g)
  is a first order reaction. After 30 min. from the start of the decomposition in a closed vessel, the total pressure developed is found to be 284.5 mm of Hg and on complete decomposition, the total pressure is 584.5 mm of Hg. Calculate the rate constant of the reaction.

  回答

  (C)

  5.2 x 10^-3 min^-1
• 19

  Write the IUPAC name for the following :

  

  回答

  A

  B