Embed Size (px)
Citation preview
PAGE: 1 CHEMISTRY & PHYSICS KEAM ANSWER KEY 2016
KEAM (MEDICAL) ANSWER KEY 2016
PAPER I – CHEMISTRY & PHYSICS
VERSION VERSION VERSION VERSION Qn. No. A1 A2 A3 A4
Qn. No. A1 A2 A3 A4
Qn. No. A1 A2 A3 A4
Qn. No. A1 A2 A3 A4
1 A B E C 31 C A C B 61 B D C E 91 D B E B 2 B E A D 32 E E E C 62 D C B A 92 B E B E 3 D A D A 33 E E E D 63 C B E E 93 C B C A 4 D E A E 34 A C D A 64 E A C C 94 B D B C 5 C D A A 35 D D D A 65 E C D B 95 A D A E 6 B C E C 36 A C B C 66 D B D B 96 D E D B 7 A B E D 37 A D E A 67 D C C C 97 E B C B 8 C E A D 38 E A D B 68 B D E A 98 A D A C 9 B C E A 39 E E A E 69 E A C E 99 C C B A 10 C D C C 40 A A B A 70 D A A E 100 D A E E 11 D D B B 41 E C A E 71 A C C C 101 C D A B 12 A C B D 42 C D B D 72 B A E D 102 E B C D 13 A E C C 43 B D D C 73 C B E B 103 B E E A 14 C C A E 44 B A D B 74 A D A D 104 E B B B 15 A A E E 45 C C C E 75 B A C D 105 B C B E 16 B C E D 46 A B B C 76 E B D E 106 D B C B 17 E E C D 47 E D A D 77 A E C B 107 D A A D 18 A E D B 48 E C C D 78 C B E D 108 E D E B 19 E A C E 49 C E B C 79 E D B C 109 B C B C 20 D D D D 50 D E C E 80 B B E A 110 D A D B 21 C A A A 51 C D D C 81 B C B D 111 C B A A 22 B A E B 52 D D A A 82 C B D B 112 A E B D 23 E E A A 53 A B A C 83 A A D E 113 D A E E 24 C E C B 54 E E C E 84 E D E B 114 B C B A 25 D A D D 55 A D A E 85 B E B C 115 E E D C 26 D E D D 56 C A B A 86 D A D B 116 B B B D 27 C C A C 57 D B E D 87 A C C A 117 C B C C 28 E B C B 58 D A A A 88 B D A D 118 B C B E 29 C B B A 59 A B E A 89 E C D C 119 A A A B 30 A C D C
60 C D D E
90 B E B A
120 D E D E
PAGE: 2 CHEMISTRY & PHYSICS KEAM ANSWER KEY 2016
QUESTIONS & DETAILED ANSWERS
1. An aqueous solution of glucose containing 60 g glucose (C6H12O6) per litre has an osmotic pressure of 5.2 bar at 300K. The concentration of the glucose solution having osmotic pressure of 1.3 bar at the same temperature is
(A) 110
M (B) 15
M (C) 120
M (D) 13
M (E) 112
M
ANSWER E
1 1
2 2
nn
π=
π
2
5.2 1/ 31.2 n
= 21n
12=
2. A solution contains 4 g of NaOH and 16.2 g of water. The mole fraction of solue and
solvent are respectively (A) 0.1, 0.9 (B) 0.2, 0.8 (C) 0.5, 0.5 (D) 0.4, 0.6 (E) 0.3, 0.7
ANSWER A
NaOH
4n 0.140
= = 2H O
16.2n 0.918
= =
3. Three elements x, y and z have the respection oxidation states –2, +3 and +6. Which one of
the following could be possible formula of the compound formed by these elements ? (A) x2 (yz4)3 (B) y2 (z4x)3 (C) x2 (zy4)3 (D) y2 (zx4)3 (E) z2 (xy4)3
ANSWER D y2(zx4)3 4. Given the standard reduction potentials F2 /F– = +2.85 V, CI– = +1.36 V. Br2 /Br– = +1.06V
and I2 /I– = +0.53 V. The strongest oxidizing and reducing agents respectively among these species are
(A) F2 and I– (B) Br2 and CI– (C) Cl2 and Br– (D) Cl2 and I2 (E) F– and I2
ANSWER A Highest reduction potential ⇒ Oxidation agent Lowest reduction potential ⇒ Reducing agent 5. At a particular temperature, the ratio of molar conductivity to conductivity of 0.1 N solution
of sodium chloride is (A) 104 cm3 (B) 103 cm3 (C) 10–1 cm3 (D) 102 cm3 (E) 10 cm3
ANSWER A
m1000K
Mλ =
4m 1000 1000 10K M 0.1λ
= = =
PAGE: 3 CHEMISTRY & PHYSICS KEAM ANSWER KEY 2016 6. In the electrolysis of aqueous sodium chloride solution, the products are (A) NaOH and Cl2 only (B) NaOH, Cl2 and O2 only
(C) NaOH, Cl2, O2 and H2 (D) Na and Cl2 only (E) NaOH, Cl2 and H2 only ANSWER E
NaOH, Cl2 and H2 only 7. The time required for 75% completion of a first order reaction is (k = rate constant)
(A) 0.6932k
(B) 0.3466k
(C) 0.6932 4k
× (D) 0.6932 34k
× (E) 1.3864k
ANSWER E
752.303 100t log
K 25=
8. The slope of Arrhenius plot (In k vs 1/T) of a first order reaction is –5 ×103. The value of Ea
of the reaction is (R = 8.3 JK–1 mol–1) (A) 41.5 kJ mol–1 (B) 83 kJ mol–1 (C) – 41.5 kJ mol–1
(D) – 83 kJ mol–1 (E) 166 kJ mol–1 ANSWER A
Slope = EaR
−
E = –R × slope 9. A reaction , P → Q has an activation energy of 25 kJ mol–1 and enthalpy change of – 5 kJ
mol–1. The activation energy for the reaction Q → P is (A) 30 J mol–1 (B) 20 kJ mol–1 (C) 15 kJ mol–1 (D) 25 kJ mol–1 (E) 30 kJ mol–1
ANSWER E f b
a aE E H− = ∆
10. Which one is not correctly matched ? (A) Lyophobic colloid – Metal sulphide sol (B) Multimolecular colloid – Gold sol (C) Lyophilic colloid – Sulphur sol (D) Marcomolecular colloid – Cellulose (E) Associated colloid – Detergent
ANSWER C Sulphur sol is Lyophobic 11. In a Freundlich`s adsorption isotherm, the slope is unity and k is 0.1. The extent of
adsorption at 2 atmosphere is (log 2 = 0.3010) (A) 0.6 (B) 0.2 (C) 0.4 (D) 0.3 (E) 0.8
ANSWER B
PAGE: 4 CHEMISTRY & PHYSICS KEAM ANSWER KEY 2016
1/ nx K.Pm
=
Slope = 1 1n
= ∴ n = 1
K = 0.1 P = 2
x 0.1 2 0.2m
= × =
12. Match the correct pair
Process Adsorbent (A) Control of humidity (i) Activated charcoal (B) Gas masks in coal mines (ii) Nickel (C) Adsorption indicators iii) Silica gel (D) Hydrogenation of oils (iv) Silver halides (A) (A) – (i) , (B) – (iii), (C) – (ii), (D) – (iv) (B) (A) – (iii) , (B) – (i), (C) – (iv), (D) – (ii) (C) (A) – (ii) , (B) – (i), (C) – (iii), (D) – (iv) (D) (A) – (iii) , (B) – (ii), (C) – (i), (D) – (iv) (E) (A) – (iv) , (B) – (ii), (C) – (iii), (D) – (i) ANSWER B
(A) Control of humidity (i) Silica gel (B) Gas masks in coal mines (ii) Activated charcoal (C) Adsorption indicators (iii) Silver halides (D) Hydrogenation of oils (iv) Nickel
13. Identify the heteroleptic complex (A) [Zn(NH3)4]2+ (B) [CoF6]3– (C) [Pt (NH3)2 Cl2] (D) [Cr(C2 O4 )3 ]3– (E) [Fe (CN)6]4–
ANSWER C Heteroleptic complexes contains more than one type of ligands
14. Among the following complexes
(i) [Ni(CO)4] (ii) [Ni(CN)4]2– (iii) [NiCl4]2–
(A) (i) and (ii) are diamagnetic but (iii) is paramagnetic (B) (i) and (iii) are diamagnetic but (ii) is paramagnetic (C) (ii) and (iii) are diamagnetic but (i) is paramagnetic (D) (i) and (iii) are paramagnetic but (ii) is diamagnetic (E) (ii) and (iii) are paramagnetic but (i) is diamagnetic
ANSWER A [Ni(CO)4] = Ni ⇒ 4s2 3d8 [Ni(CO)4] ⇒ 4S0 3d10 ⇒ Diamagnetic Ni2+ = 4S03d8 CN– ⇒ strong field ligand [Ni(CN)4]2– ⇒ dsp2 ⇒ Diamagnetic
[NiCl4] ⇒ sp3 s6 d8
PAGE: 5 CHEMISTRY & PHYSICS KEAM ANSWER KEY 2016 15. The correct formula of dichlorobis (triphenylphosphine) nickel (II) is (A) [NiCl2 (PPh3)2] Cl (B) [NiCl2 (Ph3)2] (C) [NiCl2 (PPh2)3] (D) [NiCl (PPh3)2] Cl (E) [NiCl2 (PPh3)2]
ANSWER E [NiCl2 (PPh3)2]
16. Which one of the following molecules contains carbon atoms in three hybridized states ? (A) Phenyl cyanide (B) Triphenylmethane (C) Toluene (D) Cumene (E) Phenyl methyl cyanide
ANSWER E Phenylmethyl cyamide ⇒ sp3, sp2 and sp
CN
17. The number of σ c – c, π c –c and σ c – H bonds in cumene are respectively (A) 9, 12 and 3 (B) 12, 9 and 3 (C) 9,3 and 12 (D) 3,9 and 12 (E) 12, 3 and 9
ANSWER C
CHCH3CH3
18. Among the following, the compound that possesses primary, secondary, tertiary and
quaternary carbon atoms, is (A) 2, 3 – Dimethylpentane (B) 2,3, 4 – Trimethylpentane (C) 3, 3 – Dimethylpentane (D) 2,2,4 – Trimethylpentane (E) 2,4 – Dimethylpentane-
ANSWER D CH3 CH3 | | H3C – C – CH2 – CH – CH3 | CH3 19. CH3 – CH = CH2 reacts readily with B2H6 and the product on oxidation with alkaline H2O2
gives (A) CH3 – CH(OH) – CH2OH (B) CH3 – CO – CH3
(C) CH3 – CH2 – CH2 – OH (D) CH3 – CH2 – CHO (E) CH3 – CH2 – CH2 – CHO
ANSWER C Terminal alkenes give primary alcohols on Hydroboration–oxidation reaction
PAGE: 6 CHEMISTRY & PHYSICS KEAM ANSWER KEY 2016 20. Which one of the following exhibits positive resonance effect (+R effect)? (A) –CHO (B) –CN (C) –COOH (D) –OCOR (E) –NO2
ANSWER D
–O–C–R Lone pair of Oxygen involved in +R effect
21. Finkelstein reaction is an example of (A) aliphatic nucleophilic substitution reaction (B) aliphatic electrophilic substitution reaction (C) aromatic electrophilic substitution reaction (D) aliphatic free radical substitution reaction (E) aliphatic elimination reaction
ANSWER A R–X + NaI → R – I + NaX (X = Cl or Br) 22. Consider the following haloalkanes (I) 1-Bromobutane (II) 2-Bromo-2-methylpropane (III) 2-Bromobutane The boiling points of the above isomeric haloalkanes decrease in the order (A) (I) > (II) > (III) (B) (III) > (II) > (I) (C) (II) > (III) > (I) (D) (II) > (I) > (III) (E) (I) > (III) > (II)
ANSWER E B.P decreases as branching increases 23. Which one of the following compounds will show geometrical isomerism? (A) BrCH = CHBr (B) CH3CH = CH2 (C) (CH3)2C = CHCH3 (D) CH3CH2CH = CH2 (E) 1, 2-Dimethylbenzene
ANSWER A 24. A compound ‘A’ with molecular formula C4H10O reacts instantaneously with cold HCI in
the presence of anhydrous ZnCl2 to form a compound ‘B’. ‘B’ when heated with metallic sodium in dry ether forms a compound ‘C’ Compound C is
C C Br
H H
Br C C
Br
H Br
H
PAGE: 7 CHEMISTRY & PHYSICS KEAM ANSWER KEY 2016
2
HClZnCl→
ANSWER C The given alcohol is 3º since an instantaneous reaction with Lucas’ reagent
CH3 CH3 | | CH3–C–OH CH3 – C – Cl | | CH3 CH3 CH3 CH3 CH3 CH3 | | | |
H3C–C–Cl + 2Na + Cl – C – CH3 ––→ H3C – C –– C – CH3 | | | | CH3 CH3 CH3 CH3 25. Which one of the following is an achiral molecule? (A) 2-Butanol (B) 2, 3-Dihydroxypropanal
(C) Bromochloroiodomethane (D) Ethylene glycol (E) Lactic acid ANSWER D
HO – CH2 – CH2 – OH contains no asymmetric 26. The major product obtained when 4-Chloronitrobenzene is heated with NaOH at 443 K and
then treated with dil. HCL is (A) Nitrobenzene (B) p-Aminophenol (C) Benzene (D) p-Nitrophenol (E) p-Dihydroxybenzene
ANSWER D
NO2
Cl
NaOH
443 K
NO2
ONa
HCl
NO2
OH 27. The product formed when acetone is heated with Ba(OH)2 is (A) 4-Methlpent-3-en-2-one (B) 3-Methylpent-3-en-2-one (C) Hex-3-en-2-one (D) 4-Hydroxy-4-methylpentan-2-one (E) 4-Methylpent-4-en-2-one
ANSWER A Aldol condensation
O CH3 O CH3 || | || | CH3 – C – CH3 + O = C – CH3 2( )Ba OH→ CH3 – C – CH2 – C – CH3 | OH O CH3
|| |
2H O∆
−→ CH3 – C – CH = C – CH3
PAGE: 8 CHEMISTRY & PHYSICS KEAM ANSWER KEY 2016 28. Which one is preferred reagent for the conversion of ester to aldehyde? (A) SnCl2 / HCl (B) Pd / BaSO4 (C) DIBAL – H (D) CO / HCl (E) Sn / HCl
ANSWER C Ester
2
( )( )
i DIBAL Hii H O
−→ Aldehyde
29. A compound ‘A’ with molecular formula C5H10O gives a positive 2, 4-DNP test but a
negative Tollen’s test. On treatment with sodium hypochlorite, it gives CHCl3 and compound ‘B’. Compound ‘B’ is
(A) Sodium propanoate (B) Sodium butanoate (C) Sodium acetate (D) n-Butane (E) Isobutane
ANSWER B Positive 2, 4 – DNP test ⇒ Carbonyl group. Negative Tollen’s test ⇒ No aldehydic group O | | Positive halogen test ⇒ Presence of CH3 – C – group The products are (i) chloroform and (ii) Sod. salt of acid with one carbon atom less. 30. Which of the following reactions can convert butanone to n-Butane? (I) Rosenmund’s reduction (II) Clemmensen reduction (III) Reduction with LiAlH4 (IV) Wolff-Kishner reduction Choose the correct answer from the codes given below (A) (I), (II) and (IV) (B) (I) and (III)
(C) (I), (II), (III) and (IV) (D) (II) and (IV) (E) (I) and (IV) ANSWER D
O | | – C – group reduced to – CH2 – group by Clemmensen reduction, Wolff-Kishner reduction, 31. Which of the following compounds will give propanamine in Hofmann bromamide
reaction? (A) Nitropropane (B) Propanamide (C) Butanamide (D) Propanenitrile (E) Butanamine
ANSWER C O | | – C – NH2 2Br KOH+→ – NH2 (Amine with one carbon atom less) 32. Which one is preferred reagent for the reduction of nitrobenzene to aniline? (A) H2 / Pd / Ethanol (B) H2 / Pt / Ethanol
(C) Finely divided Nickel (D) Zn / NaOH (E) Fe / HCl ANSWER E
PAGE: 9 CHEMISTRY & PHYSICS KEAM ANSWER KEY 2016
NO2
Fe/HCl
NH2
33. When aniline is treated with excess CH3I, the major product obtained is (A) N-Methylaniline (B) N, N-Dimethylaniline (C) p-Toluidine (D) 2, 4, 6-Trimethylaniline (E) Trimethylphenyl ammonium iodide
ANSWER E
NH2
CH3I
NHCH3
CH3I
NCH3CH3
CH3I
N+ CH3CH3
CH3
34. N-Phenylethanamide is treated with Br2 in acetic acid and the major product formed is
hydrolysed by dilute alkali to get compound ‘A’. Compound ‘A’ is (A) 2-Bromoaniline (B) 3-Bromoaniline (C) Aniline (D) 4-Bromoaniline (E) 4-Bromobenzoic acid
ANSWER D
NH
O
CH3
Br2/CH3COOH
NH
O
CH3
Br
H2O/OH-
NH2
Br
+ CH3COOH
35. The linkage of the two monosaccharide units in lactose is (A) C1 of one glucose with C2 of another glucose (B) C1 of one glucose with C4 of another glucose (C) C1 of glucose with C4 of galactose (D) C1 of galactose with C4 of glucose (E) C1 of galactose with C2 of glucose
ANSWER D C1 of galactose with C4 of glucose
36. Which of the following vitamin is responsible for increased fragility of RBCs? (A) Vitamin B1 (B) Vitamin E (C) Vitamin K (D) Vitamin C (E) Vitamin B6
ANSWER B Deficiency of vitamin K increases the clotting time of blood.
PAGE: 10 CHEMISTRY & PHYSICS KEAM ANSWER KEY 2016 37. Which one of the following is incorrectly matched? (A) α and β-Glucose – Anomer (B) Amylose – Starch (C) Glycogen – Animal starch (D) Cellulose – Polymer of β-D-glucose (E) Myosin – Globular protein
ANSWER E Myosin is a fibrous protein 38. The three bases present both in DNA and RNA are (A) guanine, cytosine and uracil (B) adenine, guanine and thymine (C) adenine, guanine and uracil (D) adenine, guanine and cytosine (E) adenine, thymine and uracil
ANSWER D DNA – Ad + Gua + Cy+ + Thy RNA – Ad + Gua + Cy+ + Ura 39. One of the builders present in scouring soaps is (A) Trisodium phosphate (B) Sodium sulphate (C) Sodium rosinate (D) Borax (E) Glycerol
ANSWER A Trisodium phosphate used as builders. 40. The major contributor to global warming is (A) Methane (B) Carbon dioxide (C) Ozone (D) Water vapour (E) CFCs
ANSWER B CO2 contributes about 50% of global warming 41. The number of molecules in 100 mg of heptane is ...... than those in 10 mg of propyne. (A) 4 times greater (B) 4 times lesser (C) 2.5 times lesser (D) 2.5 times greater (E) 16 times greater
ANSWER A
33
13 3
2
100 10n 10 1100 4100 10n 0.25 10 0.25
40
−−
− −
×= = = =
× ×
n1 = 4 x n2 42. The value of the de Broglie wavelength of He atom at –173oC is how many times its de
Broglie wavelength at 327oC? (A) 5 (B) 6 (C) 2 (D) 12 (E) 15
ANSWER B
1 2 2
2 1 1
v Tv T
λ= =
λ 1
2
600 6100
λ= =
λ
PAGE: 11 CHEMISTRY & PHYSICS KEAM ANSWER KEY 2016 43. Two electrons I and II have the following set of quantum numbers I = 3, 2, 0, –1/2 II = 4, 0, 0, +1/2 Which of the following statement is true? (A) Electrons I and II have same energy
(B) Electron I has lower energy than II (C) Electron I is in 3p orbital while electron II is in 4s orbital (D) Electron I has higher energy than II (E) Electron I has clockwise spin while electron II has anti-clockwise spin
ANSWER D Energy of 3 d > 4s 44. Which of the following species among the following are isoelectronic? Na+, K+, Li+, Ne, Mg2+ and Cl– (A) Na+, K+ and Li+ (B) Ne, Mg2+ and Cl– (C) Li+, Ne and Cl– (D) Na+, Ne and Mg2+ (E) K+, Cl– and Mg2+
ANSWER D Na+, Ne and Mg2+ contain 10 electrons. 45. The correct ascending order of atomic radius in the following atoms is (A) B < Be < Li < Al (B) B < Li < Be < Al (C) B < Be < Al < Li (D) Be < B < Al < Li (E) Be < B < Li < Al
ANSWER C B < Be < Li < Al
46. Which one of the following diatomic molecules has the highest dipole moment? (A) H2 (B) HF (C) HCl (D) HBr (E) HI
ANSWER B 0µ = for H2 µ = 1.78 for HF µ = = 1.07 for HCl µ = 0.79 for HBr µ = 0.38 for HI 47. The species with fractional bond order is (A) O2
+ (B) O22– (C) CO (D) He2 (E) N2
ANSWER A Number of electron in O2
+ is 15 and B.O = 2.5 48. Equal masses of a gas X and oxygen were present in a closed vessel at 25(C. The partial
pressure of oxygen was found to be (5/6) times of the total pressure. The molar mass of the gas X in g mol–1 is
(A) 64 (B) 60 (C) 160 (D) 80 (E) 128 ANSWER C
2 2O O x
x x
P n MP n 32
= = ; x5/ 6 M51/ 6 32
= = ; Mx = 5 x 32 = 160
PAGE: 12 CHEMISTRY & PHYSICS KEAM ANSWER KEY 2016 49. At constant temperature, a bulb ‘A’ of volume 100 mL containing an ideal gas was
connected to another evacuated bulb ‘B’. The pressure fell down to 40% of its initial pressure. The volume of bulb ‘B’ (in mL) is
(A) 75 (B) 150 (C) 125 (D) 200 (E) 250 ANSWER B
P1 V1 = P2V2 100 x 100 = 40 x V2 V2 = 250 ∴ Vol. of second bulb = 150 mL
50. The compressibility factor (Z) of one mole of van der Waal’s gas with negligible ‘a’ value is (A) bP/RT (B) [1 – (bP/RT)] (C) [1 + (bP/RT)] (D) (1/bP) (E) RT/bP
ANSWER C Since ‘a’ is negligible, pressure is high, high pressure Z > 1. 51. The element used in jewellery occupying the position of 6th period and 10th group in the
long form of the periodic table is (A) Ag (B) Au (C) Cu (D) Pt (E) Ir
ANSWER D 52. The increasing order of electronegativity of the three elements O, F and Na is (A) Na < O < F (B) O < F < Na (C) Na < F < O (D) F < O < Na (E) O < Na < F
ANSWER A 53. What is the IUPAC official name of element with atomic number 110? (A) Darmstadtium (B) Hassium (C) Seaborgium (D) Nobelium (E) Bohrium
ANSWER A 54. What are the constituents present in German silver? (A) Cu, Zn and Fe (B) Pb, Ag and Ge (C) Cu, Zn and Ni (D) Al, Ag and Ge (E) Ni, Zr and In
ANSWER C 55. Froth floatation is not used in the concentration of (A) Magnetite (B) Iron pyrites (C) Copper pyrites (D) Zinc blende (E) Copper glance
ANSWER A Prothfloatatron followed for sulphide are magnetite is Fe3O4. 56. The liquid alkali metal used as coolant in fast breeder nuclear reactors is (A) Lithium (B) Sodium (C) Potassium (D) Rubidium (E) Caesium
ANSWER B
PAGE: 13 CHEMISTRY & PHYSICS KEAM ANSWER KEY 2016 57. In which one of the following oxyacids, phosphorus exhibits +4 oxidation state? (A) Metaphosphoric acid (B) Hypophosphorous acid (C) Pyrophosphorous acid (D) Orthophosphorous acid (E) Hypophosphoric acid
ANSWER E Hypophosphoric acid is H4P2O6
58. When B2H6 is heated with NH3, the final product is (A) Borazine (B) Boron nitride (C) Boron trioxide (D) Boron (E) Boric acid
ANSWER A
3B2H6 + 6NH3 0180 C→ 2 B3 N3 H6 + 12H2
59. Which one of the following oxides of nitrogen has linear shape? (A) N2O3 (B) NO2 (C) N2O4 (D) N2O5 (E) N2O
ANSWER E
(Linear )N N O≡ →
60. The hybridized state of the bromine atom in BrF5 is (A) sp3d (B) dsp2 (C) sp3d3 (D) sp3d2 (E) sp3
ANSWER D Br F5 undergoes sp3d2 61. Which pair of the following 4d series of elements has the same number of electrons in 4d subshell? (A) Mo and Tc (B) Nb and Mo (C) Pd and Ag (D) Rh and Pd (E) Ru and Rh
ANSWER C Pd and Ag has 10 electrons in 4d sushell. 62. In which of the following pairs, both the ions are coloured in aqueous solution? (A) Ni2+, Ti4+ (B) Ni2+, Ti3+ (C) Sc3+, Ti3+ (D) Cr2+, Zn2+ (E) Sc3+, Mn2+
ANSWER B d0 and d10 systems are colourless. 63. In which one of the following actinoid elements 6d subshell is vacant? (A) Pa (B) Np (C) Lr (D) Cm (E) Pu
ANSWER E Pu ⇒ 5f6 7S2
PAGE: 14 CHEMISTRY & PHYSICS KEAM ANSWER KEY 2016 64. Which one of the lanthanide ions is diamagnetic? (A) Pr3+ (B) Nd3+ (C) Ce4+ (D) Er3+ (E) Sm3+
ANSWER C Ce ⇒ 4f15d1 6s2 Ce4+ = 4f0 5d0 6s2 ⇒ Diamagnetic 65. The work done on the system when one mole of an ideal gas is compressed isothermally to
a final volume of 0.01m3 at constant external pressure of 5 bar is 20 kJ. What is the initial volume of the gas?
(A) 0.045 m3 (B) 0.035 m3 (C) 0.025 m3 (D) 0.05 m3 (E) 0.04 m3
ANSWER D W = – P(V2 – V1)
( )5
15 1020kJ 0.01 V1000
− ×= −
∴ V1 = 0.05 m3 66. The values of ∆H and ∆S for the reaction C (graphite) + CO2 (g) → 2CO (g) are 170 kJ and 170 JK–1 respectively. The reaction will be spontaneous only at (A) 910 K (B) 510 K (C) 710 K (D) 1110 K (E) 810 K
ANSWER D
T = H 170000 1000KS 170
∆= =
∆
H∆ and S∆ are positive. ∴ spontaneous at a temperature greater than 1000 K. 67. The value of (∆H – ∆E) for the reaction
C6H6(l) + 712
O2(g) → 6CO2(g) + 3H2O(l) at 27°C is (R = 2 cal K–1 mol–1)
(A) 0.9 kcal (B) 9 kcal (C) – 0.9 kcal (D) – 9 kcal (E) – 1.8 kcal
ANSWER C H E∆ − ∆ = ∆ nRT = –3/2 x 2 x 10-3 x 300 = – 0.9 kcal 68. The pH of a solution obtained by mixing 60 mL of 0.1 M NaOH solution and 40 mL of 0.15
M HCl solution is (A) 10 (B) 12 (C) 2 (D) 8 (E) 7
ANSWER E N1 V1 = N2V2 M1x1V1 = M2x2V2 ∴ mixture will be neutral.
PAGE: 15 CHEMISTRY & PHYSICS KEAM ANSWER KEY 2016 69. The solubility product (Ksp) of the following compounds are given at 298 K Compound Ksp BaSO4 1.0 × 10–10 CaSO4 9.0 × 10–6 MnS 2.5 × 10–13 Ni(OH)2 5.0 × 10–16 The most soluble and least soluble compound are respectively (A) BaSO4 and CaSO4 (B) MnS and Ni (OH)2 (C) CaSO4 and MnS (D) BaSO4 and Ni (OH)2 (E) MnS and CaSO4
ANSWER C Ksp of CaSO4 = 9 x 10-6
∴ S = 6 3Ksp 9 10 3 10− −= × = × Ksp for MmS = 2.5 x 10-13 = 25 x 10-14
∴ S = 14 725 10 5 10− −× = × 70. The equilibrium constants for the following reactions N2(g) + 3H2(g) É 2NH3(g), N2(g) + O2(g) É 2NO(g)
and H2(g) + 12
O2(g) É H2O(lg) are K1, K2 and K3 respectively.
The equilibrium constant (K) for the reaction (A) K2 . K3
3 / K1 (B) K22 K3 / K1 (C) K1 . K2/K3
2 (D) K2 . K3/K1
2 (E) K1K2 / K32
ANSWER A Eq. (1) ⇒ reversed Eq. (2) ⇒ no change Eq. (3) ⇒ multiplied by 3 Add the modified equations.
32 3
01
K .KKK
=
71. Consider the following equilibrium reaction 2CO2(g) É 2CO(g) + O2(g) Le Chatelier’s principle predicts that adding O2(g) to the reaction container at constant temperature will (A) Decrease the partial pressure of CO2(g) at equilibrium (B) Increase the value of the equilibrium constant (C) Increase the partial pressure of CO2(g) at equilibrium (D) Increase the partial pressure of CO(g) at equilibrium (E) Decrease the value of the equilibrium constant
ANSWER C Addition O2 will shift the equilibrium in backward direction.
PAGE: 16 CHEMISTRY & PHYSICS KEAM ANSWER KEY 2016 72. A solution obeying Raoult’s law has an elevation of boiling point of 1(C. What is the mass percentage of solute in the solution? (molar mass of solute = 200g mol–1; Kb of solvent = 4.8 K kg mol–1) (A) 10 (B) 12 (C) 8 (D) 2 (E) 4
ANSWER E
Bb b
B A
.1000T K .M .
ω∆ =
ω = Kb = B
b bB B
.1000T K .M (100 )
ω∆ =
− ω
= B
B
4.8 1000200 (100 )
× ω ×− ω
∴ Bω = 4g
73. An electric dipole consists of two charges of 0.2 (C separated by a distance of 2.0 cm. The
dipole is placed in an external electric field of 105 NC–1. The maximum torque experienced by the dipole is
(A) 4 Nm (B) 4 × 10–7 Nm (C) 4 × 10–4 Nm (D) 4 × 10–5 Nm (E) 4 × 10–4 Nm
ANSWER E τmax, PE = (q × 2a) × E = 0.2 × 10–6 × 2 × 10–2 × 105 = 4 × 10–4 Nm
74. If conductor A is positively charged and conductor B is negatively charged, then the conductor (s)
(A) A has lost electrons (B) B has lost electrons (C) both A and B have lost electrons (D) A has lost protons (E) B has lost protons
ANSWER A A has lost electrons. It becomes positively charged B negatively charged. It gains electrons
75. Electric conductivity is the reciprocal of (A) Mobility (B) Conductance (C) Resistivity (D) Resistance (E) Current density
ANSWER C
σ = 1ρ
76. Nichrome is used as electrical heating element because of its (A) Negative temperature coefficient of resistance (B) Strong dependence of resistivity with temperature (C) Low melting point (D) Weak dependence of resistivity with temperature (E) Semiconducting nature
ANSWER D Nichrome = alloy = low value for ∝ (temperature coefficient of resistance) 77. The circuit element to which Ohm’s law is applicable is (A) Junction diode (B) Zener diode (C) Resistor (D) Transistor (E) Photodiode
ANSWER C I ∝ v I = V/R
PAGE: 17 CHEMISTRY & PHYSICS KEAM ANSWER KEY 2016 78. The magnetic field at any point on the axial line of a short bar magnet at a distance r from
its centre is proportional to
(A) r (B) 1r
(C) 2
1r
(D) r3 (E) 3
1r
ANSWER E
Baxial = 03
24
Mr
µπ
B ∝ 1r3
79. If a helium nucleus makes a full rotation in a circle of radius 0.8 m in 2 nano-second, then the magnetic induction at the centre of the circle is
(A) 2π × 10–10 T (B) 4π × 10–17 T (C) 2π × 10–17 T (D) 4π × 10–10 T (E) 1.6 × 10–10 T
ANSWER B
B = 0 0 0 22 2 2
I q ev r rt
µ µ µ= =
π
80. The vertical component of earth’s magnetic field is 13
times the horizontal component at a
certain place. Angle of dip at that place is (A) 90o (B) 45o (C) 0o (D) 60o (E) 30o
ANSWER E
tanθ = vBBH
⇒ Bv = 13
Bh ; tanθ = 13
81. Choose the wrong statement (A) Magnetic flux is a scalar quantity (B) Coefficient inductance is a vector quantity (C) The mutual inductance of a pair of solenoids depends on their relative orientation (D) Lenz law gives the direction of the induced emf (E) AC generator converts mechanical energy into electrical energy
ANSWER B L is a scalar quantity 82. Two different coils having self-inductance values L1 = 8 mH and L2 = 2 mH are kept far
apart. If the rate of change of current in the second coil is twice that in the first coil, then the ratio of induced emf in the first coil to that in the second coil is
(A) 2 : 3 (B) 1 : 2 (C) 1 : 1 (D) 2 : 1 (E) 1 : 3 ANSWER D
q = 1 1 1
2 2 2
( / ) 8 1( / ) 2 2
dI E L dI dtLdt E L dI dt
⇒ = × = ×
= 2 : 1
83. In an ac generator, mechanical energy is converted into electrical energy by virtue of (A) electrostatic (B) magnetic induction (C) electric induction (D) electromagnetic induction (E) mutual induction
ANSWER D AC generator works on the principle of electromagnetic induction
PAGE: 18 CHEMISTRY & PHYSICS KEAM ANSWER KEY 2016 84. Choose the wrong statement (A) Electromagnetic waves travel at the speed of light (B) Electromagnetic waves are transverse waves (C) The ratio of the electric field to the magnetic field in an electromagnetic wave equals
the speed of light (D) Electromagnetic waves carry both energy and momentum (E) Electromagnetic waves can be deflected by magnetic field
ANSWER E Electromagnetic waves have no charge
85. Two convex lenses of focal lengths 10 cm and 20 cm are kept in contact. The effective
power of the lens system is (A) 30 D (B) 15D (C) 20D (D) 12D (E) 25D
ANSWER B P = P1 + P2 86. The emergent ray of light after refraction at a rectangular glass slab (A) Suffers deviation (B) Suffers no lateral displacement with respect to the incident ray (C) Emerges perpendicular to the incident ray (D) Emerges parallel to the incident ray (E) Emerges along the incident ray direction
ANSWER D Incident ray and emergent ray are parallel
87. When unpolarised light is incident at Brewster’s angle on the boundary between two
transparent media, the reflected light is polarized with its electric vector in (A) a plane parallel to the plane of incidence (B) a plane 45oto the plane of incidence (C) a plane perpendicular to the plane of incidence (D) a plane 30o to the plane of incidence (E) plane 60o to the plane of incidence
ANSWER C Vibrations are perpendicular to the plane of incidence 88. The following pair of physical quantities of the photoelectric phenomenon that gives a
straight line graph is (A) intensity of radiation and photoelectric current (B) Potential of the anode and photoelectric current (C) threshold frequency and velocity of photoelectrons (D) intensity of radiation and the stopping potential (E) Frequency of incident radiation and the photoelectric current
ANSWER A
θp θp • • •
PAGE: 19 CHEMISTRY & PHYSICS KEAM ANSWER KEY 2016
Photoelectric effect i ∝ I 89. If 10% of a radioactive material decays in 10 days the percentage of the material that decays
in 20 days is (A) 20% (B) 41% (C) 81% (D) 19% (E) 90%
ANSWER D
0
910
NN
= 0
1 102
NN T
=
.......... (1)
0
' 1 10 22
NN T
= ×
.......... (2)
0
0
'N NN
−
100 = 100 81
100−
100 = 19%
90. 22Ne10 nucleus, decays into two alpha particles and an unknown nucleus. The unknown
nucleus is (A) Nitrogen (B) Carbon (C) Boron (D) Oxygen (E) Fluorine
ANSWER B 22 4 4 14
10 2 2 6Ne He He C→ + + 91. A device which is used to detect optical signals is a (A) junction diode (B) light emitting diode (C) Photovoltaic device (D) Zener diode (E)Photodiode
ANSWER E Photodiode 92. Identify the incorrect matching among the following
(A) Transistor – Switch in saturation state (B) Photodiode – Forward biased p – n junction diode (C) Zener diode – Heavily doped p – n junction diode (D) Solar cell – Unbiased photodiode (E) Light emitting diode – Heavily doped forward biased p – n junction diode ANSWER B
Photodiode → Forward brased PN junction diode
Photoelectric current
Intensity
PAGE: 20 CHEMISTRY & PHYSICS KEAM ANSWER KEY 2016 93. The angular frequency of a tuned collector oscillator having an LC feed back network is
(A) LC (B) LC (C) 1LC
(D) LC
(E) LC
ANSWER C
1LC
ω =
94. The layer which reflects HF waves efficiently during night time is (A) troposphere (B) thermosphere (C) lower part of stratosphere (D) upper part of stratosphere (E) mesosphere
ANSWER B Thermosphere 95. In a receiver, the device which changes the AM wave into a lower frequency wave before
its detection is (A) IF stage amplifier (B) amplifier (C) rectifier (D) envelope detector (E) band-pass filter
ANSWER A I.F stage amplifier 96. Digital signals (A) provide a continuous set of values
(B) can utilize decimal as well as binary systems (C) can utilize only decimal systems
(D) represent values as discrete steps (E) cannot utilize binary systems
ANSWER D Represent values as discrete steps
97. Two physical quantities P and Q have different dimensions. the physically meaningful
mathematical relation is
(A) P + Q (B) P – Q (C) PQ
(D) (P Q)
Q−
(E) (P Q)
Q+
ANSWER C
PQ
98. In one dimension, the angle between velocity vector and acceleration vector of an object is (A) either 00 or 1800 (B) between 00 and 1800 (C) between 900 and
1800 (D) more than 1800 (E) 900
ANSWER A either 0° or 180°
PAGE: 21 CHEMISTRY & PHYSICS KEAM ANSWER KEY 2016 99. If a train of length 300 m crosses a bridge at a speed of 108 km h-1 in 30 s, then the length of
the bridge is (A) 200 m (B) 600 m (C) 400 m (D) 300 m (E) 100
m ANSWER B
l + x = v × t 300 + x = 30 × 30 x = 600m
100. The y-component of the velocity of a body moving with a velocity, u 4 i 3 j→ ∧ ∧
= + ms-1 is (A) 1 ms-1 (B) 5 ms-1 (C) 4 ms-1 (D) 7 ms-1 (E) 3 ms-1
ANSWER E Uy = 3m/s 101. Two particles each of mass m1 and m2 are moving in concentric circles of radii r1 and r2
respectively such that their periods are same. Then the ratio of their centripetal accelerations is
(A) 1
2
rr
(B) 2
1
rr
(C) 1
2
r2r
(D) 1
2
2rr
(E) 1
2
rr
ANSWER A
ac = r 2
2
uTπ
ac ∝ r 1 1
2 2
ac rac r
=
102. The propulsion of a rocket is based on the principle of conservation of (A) angular momentum (B) mass (C) linear momentum (D) kinetic energy of the system (E) total energy of the system
ANSWER C Linear momentum 103. Identify the incorrect statement (A) rolling friction is always less than siding friction (B) the mechanical efficiency of a machine increases with the use of lubricants (C) inertia of a body is a measure of its mass (D) cream separator is an example of centrifuge (E) Newton’s laws hold good in a non-inertial frame
ANSWER E Newton’s I and II law hold good in inertial frame 104. A force of 1 N acting on a body of mass 2 kg produces in it an acceleration of (in ms-2) (A) 1 (B) 0.5 (C) 1.5 (D) 2 (E) 4
ANSWER B
a = 12
Fm
= = 0.5 ms–2
PAGE: 22 CHEMISTRY & PHYSICS KEAM ANSWER KEY 2016 105. When a same force of 5 N is applied to two balls A and B separately, they move along the
direction of the force with a velocity of 5 ms-1 and 10 ms-1 respectively. The rate of work done on the ball A to that on B are in the ratio
(A) 1 : 3 (B) 1 : 2 (C) 1 : 1 (D) 2 : 1 (E) 3 : 1 ANSWER B
Rate of work = Power = Fv
5 1
10 2A A
B B
P FVP FV
= = =
106. When a rigid body has neither linear acceleration nor angular acceleration then it is said to
be in (A) rotational equilibrium (B) relative equilibrium (C) mechanical equilibrium (D) partial equilibrium (E) translational equilibrium
ANSWER C No linear acceleration Fe × t = zero No angular acceleration text = zero
107. The pair of rigid bodies with mass M and radius R, having the moment of inertia 2MR
2 can
be (A) a ring and a solid cylinder (B) a ring and a hollow cylinder (C) a disc and a hollows cylinder (D) a solid cylinder and a solid sphere (E) a solid sphere and a hollow cylinder
ANSWER A
Ring about diameter I = 2
2MR
Solid cylinder about its own axis I = 2
2MR
108. Kepler’s second laws (law of areas) of planetary motion leads to law of conservation of (A) total energy (B) linear momentum (C) gravitational potential
energy (D) kinetic energy (E) angular momentum
ANSWER E
L = 2m At
∆∆
109. The ratio between the altitude and depth (<< radius of earth R) from the surface of earth at
which the change in the value of g is same, is (A) 2 : 1 (B) 1 : 2 (C) 1 : 1 (D) 2 : 1 (E) 1 :
2 ANSWER B
2h dR R
= ; 12
hd
= h = altitude d = depth
PAGE: 23 CHEMISTRY & PHYSICS KEAM ANSWER KEY 2016 110. The equation of continuity in incompressible fluid flow is based on the principle of
conservation of (A) potential energy of the fluid (B) kinetic energy of the fluid (C) total energy of the fluid (D) fluid mass (E) fluid momentum
ANSWER D Equation of continuity mass/sec = constant avρ = constant 111. The maximum length of a wire of density ρ and breaking stress S that can hang freely
without breaking is
(A) Sgρ
(B) 2S
gρ (C)
g2Sρ
(D) 3Sgρ
(E) gS2
ρ
ANSWER E
Breaking strength = Lρg L = sgρ
112. The flow of liquid in a tube is laminar, when the value of Reynold’s number lies between (A) 1000 and 3000 (B) zero and 2000 (C) 2000 and 4000 (D) zero and 3000 (E) 2000 and 5000
ANSWER B Reynold’s number < 2000 flow streamline
113. A monoatomic gas at pressure P is compressed adiabatically to 18
of its initial volume.
Then the pressure of the gas will change to
(A) 8P (B) 16P (C) 403
P (D) 225
P (E) 32 P
ANSWER E
Monoatomic gas r = 53
P1V1r = P2V2
r; P2 = P1 1
2
rVV
= P 85/3 = P × 25 = 32 P
114. In a refrigerator , if the system extracts heat Q2 from the cold reservoir and releases heat Q1
to the hot reservoir, then the coefficient of performance of the refrigerator is
(A) 1
1 2
QQ Q−
(B) 2
1 2
QQ Q−
(C) 1
2
(D) 2
1
(E) 1 2
2
Q QQ−
ANSWER B
β = 2 2
1 2wθ θ
=θ − θ
PAGE: 24 CHEMISTRY & PHYSICS KEAM ANSWER KEY 2016 115. Equal masses of a diatomic gas in separate containers undergo same change of temperature
by two different processes, one at constant volume and another at constant pressure. The ratio of the respective heats supplied is
(A) 1:1 (B) 1:2 (C) 2:5 (D) 5:7 (E) 3:5 ANSWER D
Heat at constant volume θ1 = n Cv ∆θ Heat at constant pressure θ2 = n Cp ∆θ
1
2
1 57
v
p
CC r
θ= = =
θ (rdiatomic =
75
)
116. A linear harmonic oscillator with force constant 3.2 × 106 Nm–1 and amplitude 0.01 m has a (A) maximum potential energy 80J (B) maximum potential energy 160 J (C) maximum kinetic energy 80J (D) minimum kinetic energy 160 J (E) minimum potential energy 100 J
ANSWER B Maximum potential energy 160 J
117. Motion of a planet around the sun is a (A) periodic and simple harmonic motion (B) non – periodic but simple harmonic motion (C) periodic but not simple harmonic motion (D) oscillatory and simple harmonic motion (E) non – periodic and damped harmonic motion
ANSWER C
KEmax = PEmax = 12
KA2 = 6 41 3.2 10 102
−× × × 1.6 × 102 = 160 J
118. During wave propagation in a medium, whenever the temperature of the medium changes, there is a change in
(A) time period (B) wavelength (C) frequency (D) phase (E) amplitude
ANSWER B As temperature increases, velocity increases, frequency constant, wavelength increases 119. The fundamental frequency of a closed organ pipe is 256 Hz. The unallowed overtone
frequency is (A) 512 Hz (B) 768 Hz (C) 1280 Hz (D) 1792 Hz (E) 2304 Hz
ANSWER A
Frequencies are 3 5, ,
4 4 4V V V
l l l ... 256, 3 × 256, 5 × 256 ...
120. The SI unit of surface integral of electric field is (A) Cm3 (B) V (C) Vm–1 (D) Vm (E) NC–1 m
ANSWER D
s
E ds⋅∫ = field × Area = voltm
m2 = volt – m
