Chemistry

Organic Chemistry

Question:

Match Column I with Column II.

Column I Column II
(a) Dumas method (1) AgN03
(b) Kjeldahl method (2) Silica gel
(c) Carius method (3) Nitrogen gel
(d) Chromatography (4) Free radicals
(e) Homolysis (5) Ammonium sulphate

 

Answer:

(a → 3); (b → 5); (c→ 1); (d →2); (e → 4)

Column I Column II Explanation
(a) Dumas method Nitrogen gel Used for N containing compounds
(b) Kjeldahl method

Ammonium

sulphate

Nitrogen converts to ammonium sulphate
(c) Carius method AgN03 Compound is heated in the presence of AgN03
(d) Chromatography Silica gel Adsorbent used is silica gel
(e) Homolysis                           ‘ Free radicals Free radicals are formed by homolytic fission

 

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Organic Chemistry

Q 1.

Classify the following reactions in one of the reaction type studied in this unit.
(a) CH3CH2Br + HS ———–> CH3CH2SH + Br
(b) (CH3)2C=CH2 + HCl ———–> (CH3)2CCl—CH3
(c) CH3CH2Br + HO ———–> CH2=CH2 + H2O + Br
(d) (CH3)3C—CH2OH + HBr ———–> (CH3)2 C Br CH2CH2CH3 + H2O

Q 2.

Name a suitable technique of separation of the components from a mixture of calcium sulphate and camphor.

Q 3.

In which of the following compounds the carbon marked with asterisk is expected to have greatest positive charge?

ncert-exemplar-problems-class-11-chemistry-chapter-12-organic-chemistry-some-basic-principles-10

Q 4.

Why is it necessary to use acetic acid and not sulphric acid for acidification of sodium extract for testing sulphur by lead acetate test?

Q 5.

Complete the following:(CH3COO)2 Pb + Na2S ———->      

Q 6.

The IUPAC name for
ncert-exemplar-problems-class-11-chemistry-chapter-12-organic-chemistry-some-basic-principles-2

(a) 1-Hydroxypentane-l, 4-dione
(b) 1,4-Dioxopentanol
(c) l-Carboxybutan-3-one
(d) 4-Oxopentanoic acid

Q 7.

Under what conditions can the process of steam distillation is used?

Q 8.

Describe the method, which can be used to separate two compounds with different solubilities in a solvent S.

Q 9.

In the Lassaigne’s test for ntrogen in an organic compound, the Prussian blue colour is obtaine d due to the formation of:
(a) Na4[Fe(CN)6] (b)Fe4[Fe(CN)6]3
(c) Fe2[Fe(CN)6] (d)Fe3[Fe(CN)6]4 .

Q 10.

An organic liquid decomposes below its boiling point. How will you purify it?

Q 11.

In Carius method, sulphur is estimated by precipitating it as which compound?

Q 12.

Explain hyperconjugation effect. How does hyperconjugation effect explain the stability ofalkenes?

Q 13.

ncert-exemplar-problems-class-11-chemistry-chapter-12-organic-chemistry-some-basic-principles-4

(a) 1 -Chloro-2-nitro-4-methylbenzene
(b) l-Chloro-4-methyl-2-nitrobenzene
(c) 2-Chloro-1 -nitro-5-methylbenzene
(d) m-Nitro-p-chlorotoluene

Q 14.

Covalent bonds can undergo fission in two different ways. The correct representation involving the heterolytic fission of CH3 – Br is

ncert-exemplar-problems-class-11-chemistry-chapter-12-organic-chemistry-some-basic-principles-15

Q 15.

Discuss the principle of estimation of halogens, sulphur and phosphorus present in an organic compound.

Q 16.

0 .12 g of an organic compound containing phosphorous gave 0.22 g of Mg2 P2O7 by usual analysis. Calculate the percentage of phosphorous in the compound.

Q 17.

Write the hybridized state of C atoms in the following CH2 = CH – C-N

Q 18.

ncert-exemplar-problems-class-11-chemistry-chapter-12-organic-chemistry-some-basic-principles-8

(a) 2-Ethyl-3-methylpentane
(b) 3,4-Dimethylhexane
(c) 2-sec-Butylbutane
(d) 2,3-Dimethylbutane

Q 19.

The structure of triphenylmethyl cation is given here. This is very stable and some of its salts can be stored for months. Explain the cause of high stability of this cation

Q 20.

Give a brief description of the principles of the following techniques taking an example in each  case: (a) Crystallisation (b) Distillation (c) Chromatography

Q 21.

Suggest a suitable technique for separating naphthalene from kerosene oil present in a mixture.

Q 22.

Name three types of chromatography.

Q 23.

Write the name of element which is confirmed on adding Na2[Fe(CN)5NO] in sodium extract solution due to appearance of violet colouration.

Q 24.

(a) What do you understand by Homolytic fission?
(b) What are carbanions? Give an example.

Q 25.

Explain why (CH3)3C+ is more stable than CH3C+H2.

Q 26.

Why is an organic compound fused with Sodium for testing nitrogen, halogens and sulphur?

Q 27.

Electronegativity of carbon atoms depends upon their state of hybridization. In which of the following compounds, the carbon marked with asterisk is most electronegative?
ncert-exemplar-problems-class-11-chemistry-chapter-12-organic-chemistry-some-basic-principles-6

 

Q 28.

Two or more compounds having same the molecular formula but different functional groups are called functional isomers. Which of die following pairs are not functional group isomers?
(a) II and III (b) II and IV
(c) I and IV (d) I and II

Q 29.

Identify the pairs of compounds which are functional group isomers.

Q 30.

Compounds with same molecular formula but differing in their structures are said to be structural isomers. What type of structural isomerism is shown by

ncert-exemplar-problems-class-11-chemistry-chapter-12-organic-chemistry-some-basic-principles-31

Q 31.

Resonance structures of propenal are given below. Which of these resonating structures is more stable? Give reason for your answer.
ncert-exemplar-problems-class-11-chemistry-chapter-12-organic-chemistry-some-basic-principles-46
 

Q 32.

What are hybridisation states of each carbon atom in the following compounds?  CH2=C=O, CH3CH=CH2, (CH3)2CO, CH2=CHCN, C6H6.

Q 33.

Which of the following represents the correct TUPAC name for the compounds concerned?
(a) 2, 2-Dimethylpentane or 2-Dimethylpentane (b) 2, 4, 7-Trimethyloctane or 2, 5, 7- Trimethyloctane  (c) 2-Chloro-4-methylpentane or 4-Chloro-2-methylpentane (d) But-3-yn- l-ol or But-4-ol-yne.

Q 34.

Which of the two: O2NCH2CH2O or CH3CH2O is expected to be more stable and why?

Q 35.

What are electrophiles and nucleophiles? Explain with examples:

Q 36.

Explain, why an organic liquid vaporises at a temperature below its boiling point in its steam distillation ?

Q 37.

cbse-class-11th-chemistry-organic-chemistry-basic-principles-techniques-26

Q 38.

Which gas is liberated in Kjeldhal’s method?

Q 39.

Which method is used to extract a compound in aqueous solution?

Q 40.

Which elements are estimated by Liebig’s Method?

Q 41.

Why is an organic compound fused with sodium in Lassaigne’s test?

Q 42.

How will you detect the presence of nitrogen and sulphur in Lassaigne’s extract?

Q 43.

What are electrophiles? Explain electrophile substitution reaction with the help of example.

Q 44.

cbse-class-11th-chemistry-organic-chemistry-basic-principles-techniques-35

Q 45.

Indicate the a- and n-bonds in the following molecules:
C6H6 , C6H12, CH2Cl2, CH=C=CH2, CH3NO2, HCONHCH3

Q 46.

Draw formulas for the first five members of each homologous series beginning with the following compounds,
(a) H—COOH (b) CH3COCH3 (c) H—CH=CH2

Q 47.

Identify the reagents shown in bold in the following equations as nucleophiles or electrophiles
(a) CH3COOH + HO ———–> CH3COO + H2O
(b) CH3COCH3 + CN ———–> (CH3)2 C(CN)(OH)
(c) C6H5 + CH3CO ———–> C6H5COCH3

Q 48.

Discuss the chemistry of Lassaigne’s test.

Q 49.

Explain the reason for the fusion of an organic compound with metallic sodium for testing nitrogen, sulphur and halogens.

Q 50.

Will CCl4 give white precipitate of AgCl on heating it with silver nitrate? Give reason for your answer.