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Chem2011solv
1. CET – CHEMISTRY – 2011
VERSION CODE: D – 3
1. If the energies of the two photons are in the ratio of 3: 2, their wavelengths will be in the
ratio of
1) 2: 3 2) 9: 4 3) 3: 2 4) 1: 2
Ans: (1)
hc hc 1 1
E1: E2 = : ⇒ :
λ1 λ2 λ1 λ2
1 1 λ :λ
3: 2 = : = 2 1 ∴ λ2 : λ1 = 3 : 2 or λ1 : λ2 = 2 : 3
λ1 λ2 λ1λ 2
2. Which one of these is NOT TRUE for benzene?
1) It forms only one type of monosubstituted product
2) There are three carbon-carbon single bonds and three carbon-carbon double bonds
3) Heat of hydrogenation of benzene is less than the theoretical value
4) The bond angle between carbon-carbon bonds is 120o
Ans: (2)
Benzene doesnot contain 3 single bonds and 3 double bonds. They are all partially double
due to resonance.
3. Generally, the first ionization energy increases along a period. But there are some
exceptions. The one which is NOT an exception is…..
1) Be and B 2) Na and Mg 3) Mg and Al 4) N and O
Ans: (2)
I.E. of Mg is more than that of Na. It is not an exception.
4. Out of the given two compounds, the vapour pressure of B at a particular temperature is
OH OH
1) higher than that of A NO2
O O
2) lower than that of A
NO2
3) higher or lower than A depending on the size of the vessel (A) (B)
4) same as that of A
Ans: (1)
Vapour pressure of o-nitro phenol is more than vapour presence of p-nitro phenol due to
intermolecular hydrogen bonding. As a result, it is more volatile.
1
2. 5. Increasing order of carbon-carbon bond length for the following is
C2H4 C2H2 C6H6 C2H6
(A) (B) (C) (D)
1) C < B < A < D 2) B < C < A < D
3) D < C < A < B 4) B < A < C < D
Ans: (4)
o
In C2H6, carbon-carbon bond is single (1.54 A )
o
In C6H6, carbon-carbon bond is partially double (1.39 A )
o
In C2H4, carbon-carbon bond is double (1.34 A )
o
In C2H2, carbon-carbon bond is triple (1.10 A )
6. The IUPAC name of the complex [Co (NH3)4Cl2] Cl is
1) tetraammine dichloro cobalt (III) chloride
2) dichloro tetraammine cobalt (III) chloride
3) tetraammine dichloro cobalt (IV) chloride
4) tetraammine dichloro cobalt (II) chloride
Ans: (1)
IUPAC name of [Co (NH3)4 Cl2] Cl is tetraammine dichloro cobalt (III) chloride
7. Excess of silver nitrate solution is added to 100 ml of 0.01 M Pentaaqua chloro chromium (III)
chloride solution. The mass of silver chloride obtained in grams is
[Atomic mass of silver is 108]
1) 143.5 x 10-3 2) 287 x 10-3 3) 287 x 10-2 4) 143.5 x 10-2
Ans: (2)
The reagent is [Cr (H2O)5 Cl] Cl2
2 x 100 x 0.01
No. of moles of Cl- ions present = = 0.002
1000
∴ Mass of AgCl = 0.002 x 143.5 = 0.287 = 2.87 x 10-3 g
8. The following data were obtained during the first order decomposition of 2A(g) → B(g) + C(s) at
a constant volume and at a particular temperature.
Sr. No. Time Total pressure in Pascal
1 At the end of 10 min 300
2 After completion 200
–1
The rate constant in min is
1) 69.3 2) 0.0693 3) 6.93 x 10-4 4) 6.93
2
3. Ans: (2)
2A (g) → B (g) + C (s)
2 – 2x x
At the end of reaction, only 1 mole of gas is present whose pressure is 200 pascal
∴ At the beginning of the reaction 2 moles of gas should have a pressure of 400 pascal
After time 10 minutes
No. of moles present, 2 – 2x + x = 2 – x
The pressure of 2 moles = 400
∴ 400 – x = 300
∴ x = 100
∴ pressure due to 2 – 2x moles of A = 400 – 200 = 200
2.303 ⎛ a ⎞ 2.303 ⎛ 400 ⎞ 2.303 0.693
∴k= log ⎜ ⎟ = log ⎜ ⎟ = log 2 = = 0.0693 min-1
t ⎝ a− x⎠ 10 ⎝ 200 ⎠ 10 10
9. The time required for 100% completion of a zero order reaction is
a 2k a
1) 2) ak 3) 4)
2k a k
Ans: (4)
a
Half life of a zero order reaction =
2k
a a
Time taken for completion = 2t1/2 = 2 x =
2k k
10. The activation energy of a reaction at a given temperature is found to be 2.303 RT J mol – 1.
The ratio of rate constant to the Arrhenius factor is
1) 0.1 2) 0.01 3) 0.001 4) 0.02
Ans: (1)
Ea
−
k = Ae RT
Ea
k −
= e RT
A
⎛k ⎞ −Ea
ln ⎜ ⎟ =
⎝A⎠ RT
⎛k ⎞ −Ea
2.303 log ⎜ ⎟ =
⎝A⎠ RT
⎛k ⎞ −Ea
log ⎜ ⎟ =
⎝A⎠ 2.303 RT
⎛k ⎞ −2.303 RT
log ⎜ ⎟ =
⎝A⎠ 2.303 RT
⎛k ⎞ k
log ⎜ ⎟ = -1 ∴ = 0.1
⎝A⎠ A
3
4. 11. The yellow precipitate formed during the chromyl chloride test is chemically
1) lead chromate 2) chromic acid
3) sodium chromate 4) lead acetate
Ans: (1)
Chromyl chloride + water + lead acetate → lead chromate
12. One gram of silver gets distributed between 10 cm3 of molten zinc and 100 cm3 of molten
lead at 800oC. The percentage of silver still left in the lead layer is approximately
1) 5 2) 2 3) 1 4) 3
Ans: (4)
Conc. of Ag in molten Zn
Partition coefficient =
Conc. of Ag in molten Pb
Mass of Ag in lead at equilibrium = 1 – x
Mass of Ag in Zn at equilibrium = x
x / 10 10 x
300 = =
1 − x / 100 1−x
10x = 300 – 300x
310x = 300
300 30
x= =
310 31
30 1 1
Amount of silver in molten lead = 1 – x = 1 - = ∴ of silver = x 100 = ≃ 3%
31 31 31
13. Which one of the following is true?
1) NaOH is a primary standard in volumetric analysis
2) NaOH is used in the concentration of bauxite ore
3) NaOH solution does not react with Cl2
4) Manganous hydroxide is soluble excess of NaOH solution
Ans: (2)
14. In Ramsay and Rayleigh’s isolation of noble gases from air, the nitrogen of the air is finally
converted into
1) NO and NO2 2) NaNO2 only 3) NaNO2 and NaNO3 4) NaNO3 only
Ans: (3)
15. The spin only magnetic moment of Fe2+ ion (in BM) is approximately
1) 7 2) 4 3) 6 4) 5
Ans: (4)
Fe+2 : [Ar] 3d6
It has 4 unpaired electrons ∴ μ = n (n + 2) = 4 (4 + 2) = 24 = 4.89 BM
∴ ≃ 5 BM
4
5. 16. A mixture of CaCl2 and NaCl weighing 4.44 g is treated with sodium carbonate solution to
precipitate all the calcium ions as calcium carbonate. The calcium carbonate so obtained is
heated strongly to get 0.56 g of CaO. The percentage of NaCl in the mixture is
[Atomic mass of Ca = 40]
1) 75 2) 31.5 c) 40.2 d) 25
Ans: (1)
CaO ← CaCO3 ← CaCl2
0.56 g 1g 1.12 g
⎡ 56 − 100⎤ ⎡100 → 112 ⎤
⎢ ⎥ ⎢ ⎥
⎣0.56 − 1g ⎦ ⎣ 1g → 1.12⎦
∴ Amt of NaCl = 4.44 – 1.12 = 3.32
3.32
% of NaCl = x 100 = 75
4.44
17. 50 cm3 of 0.2 N HCl is titrated against 0.1 N NaOH solution. The titration was discontinued
after adding 50 cm3 of NaOH. The remaining titration is completed by adding 0.5 N KOH.
The volume of KOH required for completing the titration is
1) 12 cm3 2) 10 cm3 3) 21.0 cm3 4) 16.2 cm3
Ans: (2)
No. of equivalents of HCl remaining after adding 50 cm3 of 0.1 N NaOH =
0.2 x 50 − 0.1 x 50 0.5
=
100 100
0.5 V x 0.5
∴ Volume of 0.5 N KOH required eq ≡
100 1000
0.5 1000
V= x = 10 cm3
100 0.5
18. The rms velocity of hydrogen is 7 times the rms velocity of nitrogen. If T is the
temperature of the gas, which of the following is true?
1) TH2 = 7 TN2 2) TN2 = TH2 3) TN2 = 7 TH2 4) TN2 = 2 TH2
Ans: (4)
CH2 TH2 x28
= 7 =
CN2 2 x TN2
14TH2
or 7 = or TN2 = 2TH2
TN2
19. 25 g of each of the following gasses are taken at 27oC and 600 mm pressure. Which of these
will have the least volume?
1) HCl 2) HBr 3) HI 4) HF
Ans: (3)
HI has the least number of moles. Therefore volume occupied is least.
5
6. 20. The amount of heat evolved when 500 cm3 of 0.1 M HCl is mixed with 200 cm3 of 0.2 M NaoH
is
1) 2.292 kJ 2) 1.292 kJ 3) 22.9 kJ 4) 0.292 kJ
Ans: (1)
40
No. of equivalents of NaOH reacting =
1000
1 eq → 57.3
40
eq → ? i.e. 2.292 kJ
1000
21. pH value of which one of the following is NOT equal to one?
1) 0.1 M HNO3 2) 0.1 M CH3 COOH
3) 50 cm3 0.4 M HCl + 50 cm3 0.2 M NaOH 4) 0.05 M H2SO4
Ans: (2)
0.1 M CH3COOH is not completed dissociated. Therefore pH will not be one.
22. A buffer solution contains 0.1 mole of sodium acetate dissolved in 1000 cm3 of 0.1 M acetic
acid. To the above buffer solution, 0.1 mole of sodium acetate is further added and dissolved.
The pH of the resulting buffer is ………
1) pKa + 1 2) pKa 3) pKa + Log 2 4) pKa = Log 2
Ans: (3)
[Salt]
pH = pKa + log
[Acid]
When extra 0.1 mole sodium acetate is added [Salt] = 0.2 mol dm-3
[Acid] = 0.1 mol dm-3
∴ pH = pKa + log 2
23. H2S is passed into one dm3 of a solution containing 0.1 mole of Zn2+ and 0.01 mole of Cu2+ till
the sulphide ion concentration reaches 8.1 x 10 – 19 moles. Which one of the following
statements is true? [Ksp of ZnS and CuS are 3 x 10 – 22 and 8 x 10 – 36 respectively]
1) Both CuS and ZnS precipitate 2) Only ZnS precipitates
3) No precipitation occurs 4) Only CuS precipitates
Ans: (1)
The ionic product for ZnS (0.1 x 8.1 x 10-19) and for CuS (0.01 x 8.1 x 10-19) exceeds their Ksp
values. Hence both get precipitated.
24. E1, E2 and E3 are the emfs of the following three galvanic cells respectively:
(i) Zn (s) |Zn2+ (0.1 M)|| Cu2+ (1M) | Cu (s)
(ii) Zn (s) |Zn2+ (1 M)|| Cu2+ (1M) | Cu (s)
(iii) Zn (s) |Zn2+ (1 M)|| Cu2+ (0.1M) | Cu (s)
Which one of the following is true?
1) E1 > E2 > E3 2) E2 > E1 > E3 3) E3 > E2 > E1 4) E3 > E1 > E2
6
7. Ans: (1)
0.059 [Cu2 + ]
E = Eo + log ∴ E1 > E2 > E3
2 [Zn2 + ]
25. 0.023 g of sodium metal is reacted with 100 cm3of water. The pH of the resulting solution is
…………
1) 8 2) 10 3) 12 4) 9
Ans: (3)
2Na + 2H2O → 2 NaOH + H2
2 x 23 2 x 40
0.023 0.04
0.04
∴ [OH-] = x 10 = 10 − 2 pOH = 2 ∴ pH = 12
40
26. Which one of the following statements is FALSE?
1) The ore is freed from almost all nonmetallic impurities.
2) During roasting, moisture is removed from the ore.
3) The concentrated zinc blende is subjected to calcinations during its extraction by
pyrometallurgy.
4) Calcination of ore is carried out in the absence of any blast of air.
Ans: (3)
In pyrometallurgy of Zn, ZnS is subjected to roasting.
27. Which one of the following sets of quantum numbers represents the highest energy level in
an atom?
1 1
1) n = 3, l = 1, m = 1, s = + 2) n = 4, l = 0, m = 0, s = +
2 2
1 1
3) n = 3, l = 0, m = 0, s = + 4) n = 3, l = 2, m = -2, s = +
2 2
Ans: (4)
‘n + l ’ = 3 + 2 = 5
Represents 3d shell which is the highest energy level.
28. When O2 is converted into O2 ; …………
+
1) bond order decreases
2) both paramagnetic character and bond order increase
3) paramagnetic character decreases and the bond order increases
4) paramagnetic character increases
Ans: (3)
O2 contains 2 unpaired electrons in ABMO, Bond order = 2
O2+ contains 1 unpaired electron in ABMO, Bond order = 2.5
7
8. 29. In chromite ore, the oxidation number iron and chromium are respectively ……..
1) +3, +6 2) +3, +2 3) +2, +3 4) +2, +6
Ans: (3)
Chromite ore FeCr2O4 i.e. FeO Cr2O3
O.N. of Fe = +2; O.N. of Cr = +3
30. The number of naturally occurring p-block elements that are diamagnetic is ………….
1) 6 2) 18 3) 7 4) 5
Ans: (4)
The group 18 elements have completely filled subshells. They are diamagnetic.
They are He, Ne, Ar, Kr & Xe.
31. The enthalpy of vaporization of benzene is + 35.3 kJ/mol at its boiling point of 800 C. The
entropy change in the transition of vapour to liquid at its boiling point is ……….
–1 –1
[in J mol K ]
1) + 100 2) – 100 3) – 342 4) + 342
Ans: (2)
ΔH = +35.3 kJ/mol
T = 80oC = 80 + 273 = 353 K
ΔH +35.3
ΔS = = = 0.1 kJ
T 353
ΔS = 0.1 x 103 J/mol/K
Entropy change in the transition of vapour to liquid is negative.
ΔS = -100
32. Based on the first law of thermodynamics, which one of the following is correct?
1) For an isochoric process, ΔU = -q 2) For an isochoric process, q = +w
3) For a cyclic process, q = -w 4) For an adiabatic process, ΔU = -w
Ans: (3)
First law of thermodynamics, Δu = q + w
Change in internal energy for cyclic process is 0
∴ q = -w
33. Consider the following gaseous equilibria with equilibrium constants K1 and K2 respectively.
1
SO2 (g) + O2 (g) ⇌ SO3 (g)
2
2SO3 (g) ⇌ 2SO2 (g) + O2 (g)
The equilibrium constants are related as ……….
1 2 1
1) K 1 =
2
2) 2K1 = K 2
2 3) K2 = 4) K 2 =
2
K2 K1
2
K1
8
9. Ans: (1)
1
SO2 (g) + O2 (g) ⇌ SO3 (g) - (1) K1
2
Equation (1) is reversed and multiplied by 2
2SO3 (g) ⇌ 2SO2 (g) + O2 (g) - (2) K2
1
∴ K2 = 2
K1
1
K12 =
K2
34. During the adsorption of Krypton on activated charcoal at low temperature; ………….
1) ΔH > 0 and ΔS < 0 2) ΔH < 0 and ΔS < 0
3) ΔH < 0 and ΔS > 0 4) ΔH > 0 and ΔS > 0
Ans: (2)
During adsorption heat is liberated hence ΔH is negative (less than zero) and entropy
decreases
35. For the reversible reaction, A(s) + B(g) ⇌ C(g) + D(g) ΔG0 = -350 kJ, which one of the following
B
statements is true?
1) The entropy change is negative
2) The reaction is thermodynamically nonfeasible
3) The reaction should be instantaneous
4) Equilibrium constant is greater then one.
Ans: (4)
A (s) + B (g) ⇌ C (g) + D (g) ΔGo = -350 kJ
Relationship between ΔGo and equilibrium constant is
ΔGo = -2.303 RT log Kp
When Kp > 1, ΔG0 is negative
36. Identify B and D is the following sequence of reactions.
CH2 = CH2 Conc. H2SO4
A
1) Ethyl hydrogen sulphate and
alcoholic KOH
D Δ H2O
2) Methanol and bromoethane
B
C
3) Ethanol and alcoholic KOH
4) Ethyl hydrogen sulphate and aqueous KOH
9
10. Ans: (3)
CH2 = CH2 ⎯⎯⎯.⎯2⎯⎯ → CH5 – CH2 – HSO4 (A) (addition reaction)
Conc H SO4
⎯
CH3CH2 – HSO4 ⎯⎯,⎯2⎯ → CH3CH2 – OH (B)
Δ HO
⎯ (hydrolysis)
PBr3
CH3CH2 – OH ⎯⎯⎯ → CH3CH2 – Br (C) (bromination)
⎯
alco. KOH (Δ)
CH3CH2 – Br ⎯⎯⎯⎯⎯⎯ → CH2 = CH2 (dehydro halogenation)
⎯
37. The compound which gives turbidity immediately with Lucas reagent at room temperature is
………
1) butan-2-ol 2) butan-1-ol
3) 2-methyl propan-1-ol 4) 2-methyl propan-2-ol
Ans: (4)
2-methyl propan-2-ol is an example for tertiary alcohol. Tertiary alcohol gives turbidity
immediately with lucas reagent
38. Ethyl benzene CANNOT be prepared by ……….
1) Wurtz-Fittig reaction 2) Wurtz reaction
3) Clemmensen reduction 4) Friedel-Crafts reaction
Ans: (2)
In Wurtz reaction haloalkanes are converted to aliphatic saturated higher hydrocarbons.
39. 1.2 g of organic compound on Kjeldahilization liberates ammonia which consumes 30 cm3 of
1 N HCl. The percentage of nitrogen in the organic compound is ………..
1) 35 2) 30 3) 20.8 4) 46.67
Ans: (1)
1.4 x Normality of acid x Volume used with NH3 1.4 x 1 x 30
Percentage of Nitrogen= = =35
weight of organic compound 1.2
40. Carbon cannot reduce Fe2O3 to Fe at a temperature below 983 K because ………
1) CO is thermodynamically more stable then Fe2O3
2) free energy change for the formation of CO is more negative then that of Fe2O3
3) iron has higher affinity towards oxygen then carbon
4) carbon has higher affinity towards oxygen then iron
Ans: (3)
0
Fe2O3
-200
-400
ΔGo 2C + O2 → 2CO
kJ/mol -600
-800
500 983 K
Temp (K)
Below 983 K, conversion of Iron to ferric oxide is more favourable.
10
11. 41. Which one of the following is NOT TRUE for the hydrolysis of t-butyl bromide with aqueous
NaOH?
1) The intermediate formed is a carbocation.
2) Reaction occurs through the SN1 mechanism.
3) Rate of the reaction doubles when the concentration of t-butyl bromide is doubled
4) Rate of the reaction doubles when the concentration of alkali is doubled.
Ans: (4)
Hydrolysis of t-butyl bromide with aqueous NaOH is an example for SN1 reaction, rate of the
reaction depends only on concentration of haloalkane.
Rate ∝ [Haloalkane]
42. Following is the substitution reaction in which ⎯CN replaces ⎯Cl
R - Cl + KCN R - CN + KCl
(alcoholic) Δ
To obtain propanenitrile, R-Cl should be
1) 1- chloropropane 2) chloroethane
3) 2-chloropropane 4) chloromethane
Ans: (2)
C2H5Cl + KCN → C2H5CN + KCl
43. The conversion of m-nitrophenol to resorcinol involves respectively
1) diazotization, reduction and hydrolysis
2) hydrolysis, diazotization and reduction
3) reduction, diazotization and hydrolysis
4) hydrolysis, reduction and diazotization
Ans: (3)
OH OH OH OH
0 - 5oC
[H] HNO2 H2O
O O O O + N2 + HCl
N N Cl OH
NO2 NH2
44. Formic acid is a stronger acid than acetic acid. This can be explained using
1) –I effect 2) +M effect 3) –M effect 4) +I effect
Ans: (4)
O
H3C C OH , methyl group is a electron releasing group in acetic acid
‘+I’
45. The reagent with which both acetaldehyde and acetone react is
1) I2/NaOH 2) Fehling’s reaction
3) Carbonic acid 4) Tollen’s reagent
11
12. Ans: (1)
O O O
Acetaldehyde and acetone due to presence of H C C
H3C C H H3C C CH3 3
group reacts with iodine in sodium hydroxide to give yellow crystals of iodoform.
46. The standard emf of a galvanic cell involving 2 moles of electrons in its rodox reaction is 0.59
V. The equilibrium constant for the redox reaction of the cell is
1) 105 2) 1020 3) 1010 4) 10
Ans: (2)
In a galvanic cell, ΔGo = -nFEo - (1)
o
Relationship between ΔG and equilibrium constant
ΔGo = -2.303 RT log kp - (2)
From (1) and (2)
-2.303 RT log kp = -nFEo
nFEo nEo 2 x 0.59
log kp = = = = 20
2.303 RT 2.303 RT 0.059
F
kp = A . L (20) = 2020
47. 9.65 coulombs of electric current is passed through fused anhydrous MgCl2. The magnesium
metal thus obtained is completely converted into a Grignard reagent. The number of moles of
Grignard reagent obtained is
–4 –4 –5 –5
1) 1 x 10 2) 5 x 10 3) 1 x 10 4) 5 x 10
Ans: (4)
96500 coulombs of electric current deposits 12 g of magnesium 9.65 coulombs of electric
9.65 x 12
current deposits = 1.2 x 10-3 g of magnesium
96500
1.2 x 10 −3
∴ The number of moles of Grignard reagent obtained is = = 0.05 x 10-4
24
–5
= 5 x 10
48. The empirical formula of a nonelectrolyte is CH2O. A solution containing 3g of the compound
exerts the same osmotic pressure as that of 0.05 M glucose solution. The molecular formula
of the compound is
1) C2H4O2 2) CH2O 3) C3H6O3 4) C4H8O4
Ans: (1)
For isotonic solution (solution with same osmotic pressure) c1 = c2
Wx WC6H12O6
=
Mx MC6H12O6
3 9
=
Mx 180
12
13. 0.05 M C6H12O6 containing 9 g of glucose
3 x 180
Mx = = 60
9
Molecular weight of a nonelectrolyte is 60
Molecular formula = n x empirical formula
Empirical formula = CH2O
Empirical formula mass = 12 + 2 + 16 = 30
molecularmass 60
n= = =2
Empirical formula mass 30
Molecular formula = 2 x CH2O = C2H4O2
49. Which one of the following is a covalent crystal?
1) Ice 2) Rock salt 3) Dry ice 4) Quartz
Ans: (4)
Lattic points mode up of nonmetal, they are held by covalent bond.
50. Which one of the following DOES NOT involve coagulation?
1) Formation of delta region
2) Clotting of blood by the use of ferric chloride
3) Peptization
4) Treatment of drinking water by potash alum
Ans: (3)
Peptization is process in which freshly formed precipitate converted to colloidal sol by adding
suitable electrolyte (peptizing agent)
51. Which of the following gives an aldehyde on dry distillation?
1) Calcium acetate + calcium benzoate 2) Calcium formate + calcium acetate
3) Calcium benzoate 4) Calcium acetate
Ans: (2)
0
(HCOO)2 Ca + (CH3COO)2 ⎯⎯⎯ → 2 CH3CHO + 2CaCO3
⎯
400 C
52. α - maltose consists of
1) two α-D-glucopyranose units with 1-2 glycosidic linkage
2) one α-D-glucopyranose units and one β-D-glucopyranose unit with 1-2 glycosidic linkage
3) two α-D-glucopyranose units with 1-4 glycosidic linkage
4) two β-D-glucopyranose units with 1-4 glycosidic linkage
Ans: (3)
CH2OH CH2OH
H H H
O O H
H H 1 4 H H
OH OH
OH
HO
O
H OH H OH
13
14. In maltose Ist carbon atom of one L – D (+) glucose unit is linked to 4th carbon atom of
adjacent glucose unit through glycosidic linkage
53. Which one of the following DOES NOT correctly match with each other?
1) Lipase-enzyme 2) Silk-polyamide 3) Oxytocin-enzyme 4) Butter-fat
Ans: (3)
Oxytocin is an example for hormone (biochemical messengers)
54. In an alkaline medium, glycine predominantly exists as/in a /an
1) anion 2) cation 3) covalent form 4) zwitterions
Ans: (1)
In alkaline medium (high pH) amino acids exists as negatively charged particle (carboxyl
group donates proton).
−
H2N – CH2 – COOH ⎯⎯ ⎯⎯→ H2N – CH2 - CO O
High pH
55. The IUPAC name of O is
1) but-1-enoic acid OH
2) but-3-enoic acid
3) prop-2-enoic acid 4) pent-4-enoic acid
Ans: (2)
O
H2C CH CH2 C OH Root word: But -
3 2 1
4 Suffix: (10) 3 – ene
(20) oic acid
IUPAC Name: But – 3 – enoic acid
Bond line natation of the above compound
O
OH
56. A solution of two liquids boils at a temperature more than the boiling point of either of them.
Hence, the binary solution shows
1) positive deviation from Raoult’s law
2) negative deviation from Raoult’s law
3) positive or negative deviation from Raoult’s law depending upon the composition
4) no deviation from Raoult’s law
Ans: (2)
Solutions boil at relatively higher temperature, vapour pressure of solution is less
14
15. O
57. Which one of the nitrogen atoms in H2N NH C NH2 is the most nucleophilic?
I II III
1) I
2) III
3) All three nitrogen atoms are equally strong nucleophilic centers
4) II
Ans: (1)
58. The maximum number of possible isomers in 1-bromo-2-methyl cyclobutane is
1) 2 2) 4 3) 16 4) 8
Ans: (2)
H
H2C C CH3
2 Number of asymmetric c-atoms = (n) = 2
1 ∴ Total number of optical isomers = 2n = 22 = 4
H2C C Br
H
59. Which one of the following is the most energetic conformation of cyclohexane?
1) Twisted boat 2) Boat 3) Half chair 4) Chair
Ans: (3)
Most energetic conformation (least stable) of cyclohexane is half chair form
60. Which one of the following is an intermediate in the reaction of benzene with CH3Cl in the
presence of anhydrous AlCl3?
+
−
a) CH3 2) Cl+ 3) 4) CH3 +
Ans: (4)
+
Ch3Cl + AlCl3 → C H3 + AlC l4
−
15