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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
(a) (b) (c) (d) CH CH C CH CH CH C CH CH CH C CH C C—CH CH 2 43. Determine the standard reduction potential for the half cell reaction, Cl 2 + 2e – 2Cl – . (Given : Pt 2+ + 2Cl – Pt + Cl 2 , E° cell = –0.15 V Pt 2+ + 2e – Pt, E° = 1.20 V) (a) 1.05 V (b) – 1.05 V (c) – 1.35 V (d) 1.35 V 44. Among 2-chloropropanoic acid, 3-chloropropanoic acid, 2,2-dichloroacetic acid and propanoic acid, the K a values will be in the order, (a) 2,2-dichloroacetic acid > 2-chloropropanoic acid > 3-chloropropanoic acid > propanoic acid (b) 3-chloropropanoic acid > 2-chloropropanoic acid > 2,2-dichloroacetic acid > propanoic acid (c) 2,2-dichloroacetic acid > 3-chloropropanoic acid > 2-chloropropanoic acid > propanoic acid (d) 2,2-dichloroacetic acid > propanoic acid > 2-chloropropanoic acid > 3-chloropropanoic acid 45. Which one of the following is employed as a tranquilizer? (a) Naproxen (b) Tetracycline (c) Chlorpheniramine (d) Equanil SOLUTIONS 1. (b): The decomposition reaction of H 2 O 2 is 2HO → 2HO+ O 2 2 2 2 Thus, 2 mol (or 4 equivalents) of H 2 O 2 would give 1 mol (22.4 L at STP) of O 2 . 1 L of 4 equivalents of H 2 O 2 has a volume strength of 22.4. Thus, 22. 4× 1. 5 1 L of 1.5 equivalents (1.5 N) of H 2 O 2 = = 8.4 4 2. (c) : Molarity of glucose in blood No.ofmoles of glucose = Volume of blood (inL) Wt.ofglucose = Mol. wt.ofglucose × Volume of blood (inL) [Mol. mass of glucose = 180 g/mol] 09 . g = 180 g/mol× 1 L = 5 × 10–3 mol L –1 = 0.005 M 3. (a) 4. (a) : If ∆ o < P, then fourth electron will go to higher energy, e g orbital. Hence, the configuration becomes t 3 2g e 1 g. 5. (b): For H-atom : 1 1 1 = RH − 2 2 λ H n1 n2 ...(i) For He + ion : 1 2 1 1 = RH × Z − 2 2 ...(ii) + n 1 n 2 λ He 1 1 ∴ λ + = λ He H × = 91. 2 × = 22. 8 nm 2 2 Z 2 ( λ H = 91.2 nm) 6. (b) : O 2 F 2 and H 2 O 2 , both have open book type structure. In O 2 F 2 , one O—O bond and two O—F bonds are lying in different planes, i.e., this molecule like H 2 O 2 has non-linear and non-planar structure. 7. (d): Adding first two equations, we have, CaC2 + 2H2O+H2→ CaOH ( ) 2+ C2H4 64 g 28 g i.e., 64 g of CaC 2 gives 28 g of C 2 H 4 . From 3 rd equation, nCH 2 4 → ( CH2CH2) n 28n g of C 2 H 4 gives 28n g of polythene i.e., 28 g of C 2 H 4 gives 28 g of polythene. Hence, 64 g of CaC 2 will give 28 g of polythene or, 64 kg of CaC 2 will give 28 kg of polythene. 2+ 8. (a) : Mg NH3 HPO 2 − + + 4 → MgNH ( 4) PO4 White ppt. 9. (c) : Greater the number of ions and greater the charge on each ion, greater will be the conductivity. The given complexes ionise as, (P) Mg[Cr(NH 3 )(NO 2 ) 5 ] Mg 2+ + [Cr(NH 3 )(NO 2 ) 5 ] 2– No. of ions = 2 14 CHEMISTRY TODAY | APRIL ‘17
Page 2 and 3: Volume 26 No. 4 April 2017 Managing
Page 5 and 6: (R) K[Co(NH ) (NO ) 4 ] 1. The volu
Page 7: 24. m-Bromoaniline can be prepared
Page 11 and 12: 20. (d) : CH 2 5 alk. KMnO 4 ( A) C
Page 13 and 14: 41. (a) : According to Gibbs’-Hel
Page 15 and 16: 5. Compound 'X' C 7 H 8 O, is insol
Page 17 and 18: (c) (d) O HC 2 O O HC 2 O O CH CH C
Page 19 and 20: 4. As 2 S 3 sol carries a negative
Page 21 and 22: 15. Cl CHONa + EtOH 2 5 Heat Possib
Page 23 and 24: (c) If θ = 10°, the charge underg
Page 25 and 26: (c) (d) NH 2 O heat NH HO 2 C CO 2
Page 27 and 28: (c) Dil. HCl followed by reaction w
Page 29 and 30: 33. Which of the following reaction
Page 31 and 32: Balz-Schiemann reaction : tetrauoro
Page 33 and 34: 26. (c) : HC 3 HC 3 -H O CH 2 3 H +
Page 35 and 36: 12. At equimolar concentration of F
Page 37 and 38: (a) 1s 2 , 2s 2 2p 6 , 3s 2 3p 6 3d
Page 39 and 40: Fraction of M present as M 2+ = 88
Page 41: 26. (b) : According to Gay-Lussac
Page 47 and 48: CONCEPT MAP PERIODICITY IN PROPERTI
Page 49 and 50: Class XII This specially designed c
Page 51 and 52: JEE MAIN / JEE ADVANCED / PETs Only
Page 53 and 54: CHEMISTRY MUSING SOLUTION SET 44 24
Page 55 and 56: Isothermal reversible expansion :
Page 57 and 58: (a) H 2 O/H + , BH 3·THF/H 2 O 2·
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22. H 2 can be obtained from 28. Th
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7. Predict the product for the foll
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7. (d) : Cyclopropane is under seve
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46. If the first and the (2n - 1) t
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1 (a) 6 2 ms − (b) 4 2 (c) 7 m s
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tension, viscous force, weight but
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(a) HN 2 SO 3 H (b) (NH 2 ) 2 CO (c
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SOLUTIONS PAPER-I 1. (a) : The phot
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11. (a, d) : As, F 1 = k 1 x, F 2 =
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Given that, at equilibrium, ⎛ n
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2 ∫ 53. (3) : (| x− 2| + [ x])
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percentage change in v = 1 2 perce
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Again, c 2 a 2 b 2 = + + 2a⋅b
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90 CHEMISTRY TODAY | APRIL ‘17
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