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Practical Organic Chemistry

In document Questions Chapter 1-10 (Page 99-107)

10

10.5 The following two compounds I and II can be distinguished by using reagent

OH

COOH

HO

COOH

(1) aq. NaHCO3 (2) Neutral FeCI3 (aq.) (FfeCI3 + NH4OH + H2O)

(3) Blue litmus solution (4) Na metal (5) HCI (ZnCI2 anhydrous) (A) 1 or 3 (B) 2 or 5 (C) 4 or 5 (D) 3 or 4

10.6 Tollen's regent (AgNO3 + NH4OH) can be distinguished between

(A) H–C–H and Ph–C–H

O O

(C)

C O D

Me C=O and

Me C=O

O

O H

O H H

O and

Ph–C–Ph and Me–C–Me

O O

(B)

(D)

10.7 Observe the4 following compound and select +Ve & –Ve tests respectively

C CH

COOH OHC

HO

(i) Na metal (ii) NaHCO3 (iii) 2,4-DNP (iv) Lucas reagent

(A) + + + – (B) + + + + (C) + – + – (D) + – – +

10.8 Consider following compounds and decide as to which of the following statements are true ?

CH = CH – C – COOH2 H

CH3

CH – C – OCH3 3 CH3 CH3

CH – C – CH OCH3 2 3 OH

CH3 CH O–C 3 C – H

(I) (II) (III) (IV)

(A) (II) gives no reaction with Na metal, however, 1 mole of (IV) on reaction with Na metal willliberate 22.4 litres of H2 gas at STP

(B) (I) will give brisk effervescence on addeition of NaHCO3 but will not bring any change in the colour of Br2 water

(C) (III) Iiberates H2 gas with Na metal, gives white precipitate with Tollen's reagent but does not respond towards lucas reagent or 2, 4-DNP test.

(D) (IV) gives turbidity with anhydrous ZnCI2

10.9 An aromatic compound 'X' (C9H8O3) turns blue litmus to red.It gives yellow precipitate with I2/ NaOH and forms Y (C8H6O4).Y forms three mononitro isomeric products. Identify X.

COOH COCH3 (A)

COOH COCH3 (B)

COOH COCH3

(C) (D) none of these

10.10 Which will not give iodoform reaction with I2/OH–?

(A) CH3COCH2CH3 (B) CH3CONH2 (C) C6H5COCH3 (D) CH3CHO

10.11 Compound Y1C7H8O is insoluble in water, dil HCI and aqueous NaHCO3.It dissolves in dilute NaOH. When Y is treated with bromine water it is converted rapidly into a compound of formula C7H5OBr3.Identfy the structure of Y

(A) OH

CH3

(B) (C) (D)

OH O – H O – CH3

CH3

CH3

10.12 Compounds I and II can be distinguished by using reagent

(I) (II)

4-Amino-2-methlbut-3-en-2-ol 4–Amino–2, 2-dimethylbut-3-yn-1-ol.

(A) NaNO2/HCI (B) Br2/H2O

(C) HCI/ZnCI2 (anhydrous) (D) Cu2CI2 + NH4OH

10.13 Compound P(C6H10) does not have any geometrical isomer. ON ozonolysis, two products R(C3H4O) and Q(C3H6O) are formed. R gives negative iodoform test while Q responds positively towards I2/NaOH solution. S, another isomer of P is an unsyumetrical alkene and on ozonolysis produces T(C6H10O2) which also gives a yellow precipitate with I2/NaOH solution and also gives positive test with Tollen's reagent. Which of the following does not represent any of the molecules amongst P,Q,R,S&T.

(A) O (B) (C) (D)

H OO H H OO H

10.14 A set of reagents (1 to 8) are successively reacted with the followit compound

OH

OH O

1. NaHCO3 2.2, 4, DNP 3.Na metal 4. AgNO3 +OH

5. Fehling's solution 6.Cu2CI2 + NH4OH 7. Br2/H2O 8. NaNO2 + HCI The reagents which give positive test with the given compound are :

(A) 1, 2, 3, 4, 5 (B) 3, 4, 5, 6, 8 (C) 1, 2, 3, 4, 8 (D) All reagents except 1 and 8

10.15 Compounds (C8H8O) X will give following laboratory tests.

Isomers FeCl3 AgNO / NH OH3 4 Na metal X Coloured solution Negative 1/2 H 2

X can be :

10.16 Which of the following alcohol will show positive iodoform test ?

CH – CH – CH3 2 – NO2

(D) none of these 10.17 The compound A gives following reactions.

Na metal

2, 4-DNP

O3

yellow orange ppt H 2gas

10.18 In compound A (C30H60O) following tests are observed negatively, A can be :

-Ve

(A) an unsaturated ether(B) an epoxide (C) a cyclic ketone (D) a cycloalkanol

10.19 A mixture of two orgnaic compound gives red coloured precipitate with cuprous chloride (ammonical) and silver mirror on heating with Zn dust and NH4CI followed by AgNO3 + NH4OH solution. The mixture contains

COOH COOH

SECTION - II : MULTIPLE CORRECT ANSWER TYPE

10.20 2D, 3D, 4D, 5D, 6-Pentahydroxy hexanal can give.

(A) Tollen's Test (B) Lucas Test (C) 2, 4-DNP Test (D) FeCI3 Test

10.21 Compound X and Y both have the same molecular formula (C4H8O). They give following observation in some lab test.

Test X Y

Br2–water positive negative

Na–metal positive negative

Lucas reagent turbidity after some time negative

lodoform test negative negative The compound X and Y are

(A) OH (B) OH (C) OH (D) O

10.22 Compound 'P' (C10H12O) evolves H2 gas with Na metal. It reacts with Br2/CCI4 to give 'Q' (C10H12Br2O). With I2/NaOH it forms iodoform and an acid 'R' (C9H8O2). 'P' has geometrical and optical isomers. The structure of 'P and R' should be

(A)

COOH

CH=CH2

(C)

CH = CH – CH – CH3 OH

(B) PH – CH = CH – COOH

(D)

CH = CH – CH3 OH

10.23 compound (X) C9H10O is inert to Br2/CCI4.Vigorous oxidation with hot alkaline KMnO4/OH yields C6H5COOH. (X) gives precipitate with 2,4-dinitrophenyl hydrazine. How can these isomers be distinguished by the usual chemical tests?

Following are possible isomkers of X : (l)

(lv) (l)

(lll)

C H – CH – CH – CHO6 5 2 2

C H – CH – C – CH6 5 2 3 O

C H – CH – CHO6 5

C H – C6 5 – CH – CH2 3 O

CH3

(I) C6H5 – CH2 – CH2– CHO

(A) I gives red ppt. with Fehling solution and II & III cand be distinguished by iodoform test (B) I & II can be distinguished by simple chemical method

(C) I & II give red ppt. with Fehling solution and III & IV can be distinguished by iodoform test (D) II give red ppt. with Fehling solution and I & IV can be distinguished by iodoform test.

10.24 Which is/are the correct method for separating a mixture of benzoic acid, p-methylaniline &

phenol.

(A) aq.NaHCO3 aq.NaOH (B) aq.HCI aq.NaHCO3 (C) aq.NaOH aq.NaHCO3 (D) aq.NaOH aq.HCI

SECTION - III : ASSERTION AND REASON TYPE

10.25 Statement -1 : Only one Aldehyde 'X' responds positively with all the tests of carbonyl compounds like Tollen's test, Fehling test, 2, 4-DNP test, as well as iodoform test.

Statement-2 : All aldehydes respond all the four tests given in assertion.

(A) Statement-1 is True, Statement-2 is True; Statement-2 is acorrect explanation for Statement-1.

(B) Statement-1 is True, Statement-2 is True; Statement-2 is NOT a correct explanation for Statement-1.

(C) Satement-1 is True, Statement-2 is False.

(D) Statement-1 is False, Statement-2 is True.

10.26 Statement-1 : A mixture os p-methylbenzoic acid and picric acid is separated by NaHCO3 solution .

Statement -2 : p-Methylbenzoic acid is soluble in NaHCO3 because it give effervesence of CO2 (A) Statement-1 is True, Statement-2 is True; Statement-2 is acorrect explanation for Statement-1.

(B) Statement-1 is True, Statement-2 is True; Statement-2 is NOT a correct explanation for Statement-1.

(C) Satement-1 is True, Statement-2 is False.

(D) Statement-1 is False, Statement-2 is True.

SECTION - IV : TRUE AND FALSE TYPE

10.27 Give the correct order of initials T or F for following statements. Use T if statement is true and F if it is false. X (molecular formula, C7H6O2) is and aromatic white solid which liberates colourless, odourless gas on rescting with NaHCO3.

S1 : Only three of th3e five functional isomers of X (including 'X' itself) will give positive 2, 4-DNP test.

S2 : The liberated colourles, odourless gas will contaning radioactive 14C.

S3 : Except 'X', no other functional isomer will liberate colourless odourless gas with NaHCO3.

S4 : The DU of higher homolog of 'X' will be four.

(A) TTTF (B) FTTF (C) FTTT (D) TTFF

SECTION - V : COMPREHENSION TYPE

Comprehension # 1

Observe the following sequence of reactions P (C H Br)9 9 R + Q

(s) + Ag

reductive O / Zn,H O3 2

(i) Tollen's Reagent (ii) H+

P shows geometrical isomersm. Q gives positive Tolen's test and the oxidation product of Tollen's test followed by acidification is the strongest acid among its all position isomers. R gives positive lab tests with 2,4-DNP, Fehling solution and I2/NaOH reagents.

10.28 The compound P can be

(A) Br

CH – CH = CH2 2

(B) Br

CH= CH – CH3

(C) Br CH= CH – CH3

(C)

CH= CH – CH3

Br 10.29 What could be the structure of Q ?

(C)

CHO

CH3 (B)

(A) (D)

CHO Br COOH

CH3 CHO

Br

10.30 Identify the structure of R

(A) HCOOH (B) CH3CHO (C) BrCH2 – CHO Comprehension # 2

An aromatic compound T (C10H10O2) give 2 moles of CHI3 and compound U (C8H4O4Na2) On treatment with I2 and NaOH. After acidification U gives two mononitro produicts on nitration.

10.31 Compound (T) can aoso be obtained by ozonolysis of V, in this ozonolysis one mole of OHC – CHO is obtained alongwith (T). Possible structure for Compound V could be

CH3 CH3 (A)

(C)

CH3

CH3 CH3

CH3 (B)

CH3 (D) CH3

10.32 Which of the following statement is true

CH3 C CH3 O O

(A) T is C

(B) Compound (V) decolourises pink colour of diluted solution lkof KMnO4.

(C) All isomers (only acidic) of U after acidification gives one mole of CO2 with NaHCO3 (D) After acidification of (U), it is most acidic in its all other isomers.

10.33 Compound U is

O (A)

COONa

O C H

||

(B)

COONa COONa

(C)

COONa

COONa

(D)

COONa

COONa

SECTION - VI : MATRIX - MATCH TYPE

10.34 X(C8H14) by ozonolysis forms Y[C8H14O2]. Y on reaction with NaOI followed by acidification gives CHI3 and compound Z on strong heating forms W.

Column-I Column-II

(A) Compound X (p) Bayer's Test

(B) Compound Y (q) NaHCO3

(C) Compound Z (r) 2, 4-DNP

(D) Compound W (s) Iodoform Test

(t) Na Metal

10.35 Match the following : (More than one option in column - II may match with single option in column-I)

Column - I Column - II

(A) Sodium metal

(B) Sodium bicarbonate

(C) 2, 4-Dinitrophenylhydrazine

(D) Lucas reagent

(X)

O

C C – H

(Y)

CH3 CH3 OH C –

(Z) OHC

C CH COOH

(W)

CH = CH2 OH H CO3

C O

SECTION - VII : SUBJECTIVE ANSWER TYPE SHORT SUBJECTIVE :

10.36 A water insoluble organic mixture contained following compounds

(1) = Benzoic acid (2) = salicylaldehyde

(3) = p-Hydroxybenzaldehyde (4) =a-Naphthylamine (5) = Naphthalene

The following sequence of reagents are uksed to separate this mixture

1 + 2 + 3 + 4 + 5 mixture (Step-X) aq. HCI

[Insoluble] [Soluble]*

(Step-Y) aq. NaHCO3

[Insoluble] [Soluble]*

(Step-Z) aq. NaOH

[Insoluble]* [Soluble]

(Step-W) Steam distillation

[distilled]* [left behind]

Fill up the serial number of starred compound ontained in the steps X, Y, Z and W reapectively.

X Y Z W

10.37 How many acidic H is present in given compound.

O OH

O

OH

10.38 How many CHI3 will be released from the given compound.

O

||

O

|| l / NaOH2

10.39 How many molecule of phenyIhydrazine is used to form osazone from glucose.

Hint :

CHO

H OH

HO

CH OH2 OH OH H H

H

3Ph–NH–NH2

CH OH2 N––NH

N––NH HO

H OH

H

H

OH

+ Ph––NH + NH2 3

10.40 How many CHI3 will be released from given compound.

|| ||

O O

H N2 OCH3

O O

In document Questions Chapter 1-10 (Page 99-107)

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