Objective questions on chemistry for iitjee pdf'

PART A

1.

N

O + CH2 COCl

Et3 N H2 O

CH2 COCl

O

C10 H12 O3 (P)

O O

O

O

A.

B.

O

O

O

O

C.

O

D.

OH

OH

D O

O

2.

The compound Z will be:

OH−

X

CH2

CH H2 O

COCH3

Y

dil. NaOH D2 O

Z

O

O

A.

O

B. O O

O D O−

C.

D. O

O

O

C

C

O

3.

Ph

Ph + Ph

CH2

C

CH2

Ph

What is the product of the above reaction?

NaOH C2 H5 OH

Ph Ph Ph A.

Ph B.

Ph

Ph O

O

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Ph Ph Ph C.

Ph D.

Ph

Ph O

O

O

C2 H5 MgBr H3 O+

4.

B

O What is the compound B? OH A.

H5 C2

OH

H5 C2 O B. C2 H5 OH OH C.

H5 C2

CH

CH2 CH2 CH2 OH

O D. C2 H5 C2 H5

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O D 5.

O

A

H2 O

OH−

A

O

B

dil.NaOH X ∆ What is the product X of the above reaction?

B

O O−

A. O O

B. O O−

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O D

C. O O D

D. O

O

6. D

EtBr

CH3

LDA −780 C

C

NaOEt/EtOH room temp.

Then products B and D are respectively: O H5 C2

A.

O C2 H5 CH3

CH3

and

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A

EtBr

B

O

O C2 H5 CH3

B.

H5 C2

CH3

and O C2 H5 CH3

C.

Both O H5 C2

D.

CH3

Both

7. Pick the choice that tells the product and the title of the reaction: O O NaH + OC2 H5

H5 C2 O

O

A. COOC2 H5 (Crossed Claisen Condensation) Page 6

OC2 H5

OC2 H5 B.

(Retro-Aldol Condensation) OC2 H5 OC2 H5

C.

(Claisen-Schmidt Condensation) O OH

and

D.

HO

C2 H5

(Cannizaro reaction)

8. A. dihalogen derivative(A) of a hydrocarbon having two C-atoms reacts with alc.KOH and forms another hydrocarbon which gives a red ppt. with ammoniacal Cu2 Cl2 . Compound A. gives an aldehyde when treated with aq. KOH. The IUPAC Name of A. is x,y−dichloroethane, x+y is A.

2

B.

3

C.

4

D.

6

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9. For the reaction A(g) B(g) at equilibrium, the partial pressure of B. is found to B(g) is be one fourth of the partial pressure of A. S of the ∆Go for the reaction A(g) RTlnX. Then the value of X will be A.

2

B.

3

C.

4

D.

6

10. The half life period and the initial concentration for a reaction are as follows. The order of the reaction is initial concentration : 350 540 158 t1/2 : 425 275 941 A.

2

B.

3

C.

4

D.

6

11. Gold has a close-packed structure which can be viewed as spheres occupying 0.74 of the total volume. What is the radius of the gold ion if the density of gold is 19.3g/cc?(Au=197 amu) A.

1.439 × 10−8 cm

B.

4.07 × 10−8 cm

C.

1.017 × 10−8 cm

D.

8.23 × 10−8 cm

12. Pure benzene freezes at 5.3o C. A. solution of 0.223 g of phenylacetic acid C.6 H5 CH2 COOH in 4.4 g of bezene (Kf =5.12 K kg mol−1 ) freezes at 4.47o C. From this observation, one can conclude that

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A.

Phenyl acetic exists as such in benzene

B.

Phenyl acetic acid undergoes partial ionisation in benzene

C.

Phenyl acetic acid undergoes complete ionisation in benzene

D.

Phenyl acetic acid dimerizes in benzene

CF3 CO3 H H2 O

13.

A.

A. and B. are respectively OH

OH

A.

and OH

B.

and OH O

OH C.

and OH OH

D.

O

OH and

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Conc. H2 SO4 ∆

B.

H

H

14. Ph

CH3

Lucas reagent

m(all compunds possible)

Fractional distillation

CH3 OH Then the value of n is A.

2

B.

3

C.

4

D.

5

Paragraph for Question Nos. 15 to 17

KMnO4 ,cold NaIO4

[Q]C11 H12 O2

NaOH H+ ,∆

[R]C11 H12 O2

O [R]

CH3 MgBr(excess) HBr

[S]C13 H9 BrO

NaH

Answer the questions based on the above passsage 15. The compound [S] is

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n

CH2 OH

OH C2 H5

A.

CH2 Br

B.

OH CH2 OH CH3

CH2 Br OH Br

C.

CH3

Br

D. OH

OH

16. In the transformation of [Q] into [R], which of the following statements are correct.

A.

Hydride formation is rate determining

B.

Attack of OH− is rate determining

C.

Reaction is independent of the OH− concentration

D.

Reaction is independent of the reactant concentration

17. Compound [R] is

O

O

A.

B. O

O

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CH3 OH

C.

O

D.

O

OH CH3

18. Pure Na2 C2 O4 and KHC2 O4 .H2 C2 O4 are mixed in such a proportion that each gram of the mixture reacts separately with equal volumes of 0.1 M KMnO4 and 0.1 M NaOH. Suppose x is the ratio of the mass of Na2 C2 O4 and KHC2 O4 .H2 C2 O4 . Then find [x] where [.] represents the gif.

A.

2

B.

4

C.

5

D.

3

19. In Kjeldahl’s method of estimation of nitrogen, K2 SO4 acts as A.

an oxidising agent

B.

boiling point elevator

C.

boilling point depressor

D.

catalytic agent

20. Number of π-bonds in Fe2 (CO)9 is X and X n =3, then value of n will be A.

4

B.

5 Page 12

C.

2

D.

3

21. In homologues series of ethers starting from the first to seventh member how many member(s) can exhibit metamerism as well as optical isomerism?

A.

4

B.

5

C.

2

D.

3

22. Which of the following statements is correct about the colloids?

A.

Lyophillic sols have almost similar stability than lyophobic sols

B.

Greater extent of Tyndall effect is observed in lyophillic sols

C.

Lyophillic sols have large particle size than that of lyophobic sols in general

D.

The charge on the lyophobic sols is independent of the pH

O O

O

O

O

O (T)

O

O

O

23.

(P)

(R)

O (Q)

(S)

Which of the following statements is true for the compounds above?(More than one option may be correct) A. Compound (P) has a higher reduction potential than (Q) B. Compound (T) has a higher reduction potential than (S) Page 13

C. Compound (R) has highest reduction potential among (P), (Q) and (R) D. Compound (P) has higher tendency to undergoe enolization than compound (Q)

24. 0.98 g chloroplatinate salt of a monoacidic base when ignited, left 0.39 g of platinum residue. The relative molecular mass of the base is A.

40

B.

80

C.

160

D.

240

25. Which of the following fails the azo-dye test?

NH2

NH2

B.

A.

NH2

NH2

NH2

C.

NH2

D.

NH2

26. For a fairly concentrated solution of a weak electrolyte Ax By , the degree of dissociation is given by

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α=

q

Keq xy/C.

α=

q

Keq .C./xy

C.

α=

q

Keq /C.(x + y)

D.

α = Keq /C x+y−1 xx y y

A. B.

1/x+y

27. A. certain compound was known to have a formulae which could be represented as [PdCx Hy Nz ](ClO4 )2 Analysis shed that the compound contained 30.15% carbon and 5.06% hydrogen. When converted to the corresponding thiocyanate [PdCx Hy Nz ](SCN2 )2 , the analysis was 40.46% carbon and 5.94% hydrogen. Calculate the values x,y and z respectively.

A.

12, 28, 4

B.

14, 26, 2

C.

14, 28, 4

D.

12, 26, 3

28. In an oil drop experiment, the terminal velocity of an oil droplet was observed to be 1.00 mm/s. The density of the oil is 0.850 g/cm3 , and the viscosity of air is 1.83×10−5 .

Calculate the mass of the air droplet.

A.

1.10×10−6 g

B.

1.10×10−6 kg

C.

1.10×10−15 kg

D.

1.10×10−13 kg

29. Examples of isoters are A.

CO2 and SO2

B.

CO2 and N2 O Page 15

C.

NO2 and SO2

D.

all of these

30. Novolac is A.

linear condensation product of phenol and formaldehyde

B.

cross linked condensation product of urea and formaldehyde

C.

cross linked condensation product of phenol and formaldehyde

D.

linear condensation product of urea and formaldehyde

31. The number of S-O-S bonds in Îł-SO3 is A.

0

B.

2

C.

3

D.

1

32. 7.5 mL of gaseous hydrocarbon was exploded with 36 mL of oxygen. The volume of gases on cooling was found to be 28.5 mL,15 mL of which was absorbed by KOH and the rest was absorbed by a solution of alkaline pyragallol. If all volumes are measured under the same conditions, no. of H atoms in the hydrocarbons is A.

5

B.

4

C.

6

D.

7

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33. In a gravimetric determination of phosphorus, 0.248 g of an organic compound was strongly heated in a Carius tube with concentrated nitric acid. Phosphoric acid so produced was precipitated as MgNH4 PO4 which on ignition yielded 0.444 g of Mg2 P2 O7 .

The percentage of phosphorus in the compound is given by x×10. Value of x is A.

5

B.

4

C.

6

D.

7

34. After electrolysis of a sodium chloride (NaCl) solution with inert electrodes for a certain period of time, 600 mL of the solution was left which was found to be 1 N in sodium hydroxide, During the same time 31.8 g of Cu was deposited in a Cu voltameter in series with the electrolytic cells. The percentage of theoretical yield of the sodium hydroxide obtained is x×10. Value of x is given by A.

5

B.

4

C.

6

D.

7

35. Enthalpy is equal to A.

T2 [∂(G/T)/∂T]P

B.

-T2 [∂(G/T)/∂T]P

C.

T2 [∂(G/T)/∂T]V

D.

-T2 [∂(G/T)/∂T]V

36. The emf of the cell, H2(g) |Buffer||Normal Calomel Electrode is 0.720 volt at 40o C. when the barometric pressure is 760 mm. The pH of the buffer solution is(Ecalomel =0.28 volt)

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A.

5

B.

4

C.

6

D.

7

37. The density of an equilibrium mixture of N2 O4 and NO2 at 1 atm and 348 K is 1.84 g/L. Kc for the equilibrium is A.

12

B.

9

C.

6

D.

8

38. Bromine is added to cold dilute aqueous solution of NaOH and the mixture is boiled.

The greatest difference between the various oxidation states of bromine is A.

5

B.

4

C.

6

D.

7

39. Which of the following reactions will not succeed?

A.

CH3

CH2

Cl + NaI

B.

CH3

CH2

Br + LiI

C.

CH3

CH2

I + LiCl

D.

CH3

CH2

I + NaCl

acetone acetone acetone acetone

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40.

NH

2HCl H2 O

NH

The product of the above reaction sequence is

N

N

A.

NH2

NH2

B.

NH2 C. (2 moles)

D.

41. The monomer of polymer orlon is A.

vinylidene chloride

B.

methylmethacrylate

C.

acrylonitrile

D.

propylene

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COOH I2 A. NaHCO3

42.

Then the major product A. is I

I

O

O A.

O

O B.

I

COOH

COOH

I C.

I D.

43. Given is the pKa for the following organic compounds

Ph H

CH3 Ph

pK1 pK2

pK3

Given the quantitites α=pK1 /pK2 , β=pK1 /pK3 , and γ=pK3 /pK2 then which of the statement given below is true?

A. α > β and α > γ Page 20

B. α > β and γ > α C. β > γ and α > γ D. β > γ and γ > α

44. Given is the compound N(Me)2

N(Me)2

CH3 O

OCH3

Assertion (A) : The above compound is practically monoacidic.

Reason (R) : One of the nitrogen is out of plane with respect to the other nitrogen.

Which of the above statements is correct?

A. A is correct and R is the correct explanation of A. B. A and R both are correct but R is not the correct explanation of A. C. A is correct but R is false.

D. A is false but R is true.

45. Among the 3d transition metals Sc, Ti, V and Cr which has the most negative lattice enthalpy?

A. Sc B. Ti C. V D. Cr

46. Sanger’s reagent is used for the identification of : A. N-terminal of a peptide chain B. C-terminal of a peptide chain Page 21

C. side chain of a amino acid D. molecular weight of the peptide chain

47. If the Aufbau rule is not followed in filling of orbitals then the block of the element will change in

A. K(19) B. Sc(21) C. V(23) D. Ni(28)

48. What is the Kb of a weak base that produces one OH− per molecule if a 0.050 M solution is 2.5% ionized?

A. 7.8 × 10−8 B. 1.6 × 10−6 C. 3.2 × 10−5 D. 1.2 × 10−3

49. Which of the following statements given below is true ?(More than one option may be correct) A. Equilibrium of a reaction is always affected by temperature.

B. The order of pre exponential factor is of the order 105 .

C. Units of A for a zero order reaction is mol.L−1 .s−1 .

D. If a reaction is an elementary bimolecular process then it obeys second order kinetics while the converse is not true.

50. The disulfide bonds which stabilize the structure of many proteins are due to A. Due to oxdiation of two sulfate moieties Page 22

B. Oxidation of thiol moiety of cysteine C. Condensation of two methionene residues D. Condensation of two serine residues

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