An aqueous solution containing 0.10 g KIO3 (formula weight = 214.0) was treated with an excess of KI solution. The solution was acidified with HCl. The liberated I2 consumed 45.0 mL of thiosulphate solution to decolourise the blue strach-iodine complex. Calculate the molarity of the sodium thiosulphate solution.
Answer
(D)
0.0623 M
2
The orbital diagram in which the Aufbau principle is violated is
Answer
(B)
3
Interpret the non-linear shape of H2S molecule and non-planar shape of PCl3 using valence shell electron pair repulsion (VSEPR) theory. (Atomic numbers : H = 1, P = 15, S = 16, Cl = 17)
Answer
A
B
C
4
The rate constant of a reaction is 1.5 $$\times$$ 107 s-1 at 50oC and 4.5 $$\times$$ 107 s-1 at 100oC. Evaluate the Arrhenius parameters A and Ea.
Answer
(A)
A = 5.42 × 1010 s-1, Ea = 2.2 × 104 J mol-1
5
Find the solubility product of a saturated solution of Ag2CrO4 in water at 298 K if the emf of the cell Ag|Ag+ (satd. Ag2CrO4 soln.) || Ag+ (0.1 M) | Ag is 0.164 V at 298 K.
Answer
(C)
2.287 x 10-12
6
Calculate the equilibrium constant for the reaction:
2Fe3+ + 3I- $$\leftrightharpoons$$ 2Fe2+ + $$I_3^-$$. The standard reduction potentials in acidic conditions are 0.78 V and 0.54 V respectively for Fe3+ | Fe2+ and $$I_3^-$$ | I- couples.
Answer
(C)
108
7
A solution of a nonvolatile solute in water freezes at -0.30oC. The vapour pressure of pure water at 298 K s 23.51 mm Hg and Kf for water is 1.86 K kg mol-1. Calculate the vapour pressure of this solution at 298 K.
Answer
(D)
23.44 mm Hg
8
Hydrogen peroxide acts both as an oxidising and as a reducing agent in alkaline solution towards certain first row transition metal ions. Illustrate both these properties of H2O2 using chemical equations.
Answer
(D)
H2O2 can act as both an oxidizing and reducing agent in alkaline solutions, depending on the reactant.
9
Work out the following using chemical equation :
Chlorination of calcium hydroxide produces bleaching powder.
Answer
(A)
Ca(OH)₂ + Cl₂ → Ca(OCl)₂ + H₂O
10
Highly pure dilute solution of sodium in liquid ammonia
Answer
A
B
11
Read the following Assertion and Reason and answer as per the options given below
Assetion: LiCl is predominantly a covalent compound
Reason : Electronegativity difference between Li and Cl is too small
Answer
(C)
If assertion is correct but reason is incorrect
12
The geometry and the type of hybrid orbital present about the central atom in BF3 is
Answer
(B)
trigonal planar, sp2
13
ASSERTION:
Nuclide $${}_{13}^{30}Al$$ is less stable than $${}_{20}^{40}Ca$$
REASON:
Nuclides having odd number of protons and neutrons are generally unstable.
Answer
(C)
If assertion is correct but reason is incorrect.
14
Which of the following statement(s) is (are) correct?
Answer
A
B
C
15
Decrease in atomic number is observed during
Answer
A
C
D
16
The energy of an electron in the first Bohr orbit of H atom is -13.6 eV. The possible energy value(s) of the excited state(s) for electrons in Bohr orbits of hydrogen is (are)
