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32. The final product formed when boric acid is strongly
heated is
(a) HBO 2 (b) B 2 O 3
(c) H 2 B 4 O 7 (d) H 3 BO 4
33. Given :
E° Cr 3+ /Cr = – 0.74 V, E° MnO
–
4 /Mn 2+ = 1.51 V
E° Cr2 O 2– = 1.33 V, E°
7 /Cr3+ Cl /Cl – = 1.36 V
Based on the given data, strongest oxidising agent
will be
(a) Cl – (b) Cr 3+ (c) Mn 2+ (d) MnO – 4
34. Sulphur trioxide can be obtained by which of the
following reaction?
∆
(a) CaSO 4 + C →
∆
(b) Fe 2 (SO 4 ) 3 →
∆
(c) S + H 2 SO 4 →
∆
(d) H 2 SO 4 + PCl 5 →
35. Which of the following statements is not true
regarding (+)-lactose?
(a) (+)-Lactose contains 8 –OH groups.
(b) On hydrolysis (+)-lactose gives equal amounts
of D-(+)-glucose and D-(+)-galactose.
(c) (+)-Lactose is a β-glycoside formed by the
union of a molecule of D-(+)-glucose and a
molecule of D-(+)-galactose.
(d) (+)-Lactose is a reducing sugar and does not
exhibit mutarotation.
36. The equilibrium constant (K) for the reaction,
HA + B BH + + A – is 100. If the rate constant for
the forward reaction is 10 5 , then the rate constant
for the reverse reaction will be
(a) 10 7 (b) 10 –3 (c) 10 3 (d) 10 –5
37. A mixture of ethane (C 2 H 6 ) and ethene (C 2 H 4 )
occupies 40 L at 1.00 atm and 400 K. The mixture
reacts completely with 130 g of O 2 to produce CO 2
and H 2 O. Assuming ideal gas behaviour, the mole
fraction of C 2 H 4 in the mixture is
(a) 0.66 (b) 0.34
(c) 0.50 (d) 0.84
38. Two liquids X and Y form an ideal solution.
The mixture has a vapour pressure of 400 mm at
300 K when mixed in the molar ratio of 1 : 1 and
a vapour pressure of 350 mm when mixed in the
molar ratio of 1 : 2 at the same temperature. The
vapour pressures of the two pure liquids X and Y
respectively are
(a) 250 mm, 550 mm
(b) 350 mm, 450 mm
(c) 350 mm, 700 mm
(d) 550 mm, 250 mm
39. Li 2 O is one of the most efficient absorbent for CO 2 in
spacecrafts, in terms of absorbing capacity per unit
mass. If the reaction is Li 2 O + CO 2 → Li 2 CO 3 ,
what is the absorption efficiency of pure Li 2 O
(i.e., litres of CO 2 per kg of Li 2 O)?
(a) 746.66 L/kg (b) 7466.6 L/kg
(c) 74.66 L/kg (d) None of these
40. Due to inert pair effect,
(a) heavier p-block elements show lower oxidation
state as stable oxidation state
(b) heavier p-block elements show higher oxidation
state as stable oxidation state
(c) strong shielding effect by inner penultimate
electrons is observed
(d) the oxidation state is equal to the valence shell
electrons.
41. ∆H and ∆S for the reaction,
Ag 2 O (s) → 2Ag (s) + 1/2 O 2(g)
are 30.56 kJ mol –1 and 66.00 J K –1 mol –1 respectively.
The temperature at which the free energy change
for the reaction will be zero is
(a) 463 K
(b) 35440 K
(c) 20 K
(d) 483 K
42. An organic compound ‘X’ on treatment
with hydrogen and platinum catalyst,
absorbs 5 equivalents of hydrogen to give
n-butylcyclohexane. When ‘X’ is treated with
silver nitrate in ethanol, a white precipitate is
formed. The precipitate is found to be soluble
in dilute acid. Treatment of ‘X’ with an excess of
ozone, followed by dimethylsulphide and water,
gives following products,
O
O
HC CH 2
CH 2
C CH,
O O O
HC C OH,
HC
Hence, compound X is
O
OH
O
HC
O
CH
CHEMISTRY TODAY | APRIL ‘17 13