Chemistry

Organic Chemistry

Question:

What is the basic principle of chromatography?

Answer:

Chromatography is based on the principle of differential adsorption.

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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.

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 4.

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 5.

Identify the pairs of compounds which are functional group isomers.

Q 6.

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

Q 7.

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

Q 8.

Which of the following compounds contain all the carbon atoms in the same hybridization state?
ncert-exemplar-problems-class-11-chemistry-chapter-12-organic-chemistry-some-basic-principles-19
 

Q 9.

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 10.

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 11.

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

Q 12.

Which of the following^ the correct IUPAC name?
(a) 3-Ethyl-4,4-dimethylheptane
(b) 4,4-Dimethyl-3-ethylheptane
(c) 5-Ethyl-4,4-dimethylheptane
(d) 4,4-Bis(methyl)-3-ethylheptane

Q 13.

In an estimation of sulphur by Carius method, 0.468 of an organic sulphur compound gave 0.668 g of barium sulphate. Find the percentage of sulphur in the compound.

Q 14.

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

Q 15.

Which gas is liberated in Kjeldhal’s method?

Q 16.

Give equation for the following:
(i) Electrophilic Substitution
(ii) Nucleophilic Substitution

Q 17.

(a) Which is more suitable method for the purification of a compound in liquid state which decomposes at or below its boiling point?
(b) How will you separate a mixture of ammonium chloride and common salt?

Q 18.

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 19.

In which of the following representations given below spatial arrangement of group/atom is different from that given in structure ‘A'?

ncert-exemplar-problems-class-11-chemistry-chapter-12-organic-chemistry-some-basic-principles-21

Q 20.

Explain how is the electronegativity of carbon atoms related to their state of hybridization in an organic compound?

Q 21.

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 22.

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

 

Q 23.

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 24.

What is the relationship between the members of following pairs of structures? Are they structural or geometrical isomers or resonance contributors?
cbse-class-11th-chemistry-organic-chemistry-basic-principles-techniques-10

Q 25.

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

Q 26.

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 27.

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

Q 28.

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

Q 29.

Write all structural isomers of molecular formula C3H6O.

Q 30.

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

Q 31.

(a) What is Lassaigne’s extract? Will NaCN give a positive Lassaigne’s test for nitrogen?
(b) Which colour will appear in the Lassaigne's test if the compound contains both nitrogen  and sulphur.  
(c) Why is Lassaigne’s extract prepared in distilled water? Can we detect oxygen in a compound by Lassaigne’s test?

Q 32.

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

Q 33.

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 34.

Ionic species are stabilized by the dispersal of charge. Which of the following carboxylate ions is the most stable?

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

Q 35.

For testing halogens in an organic compound with AgN03 solution, sodium extract (Lassaigne's extract) is acidified with dilute HN03. What will happen if a student acidifies the extract with dilute H2S04 in place of dilute HN03?

Q 36.

What is the hybridization of each carbon in H7C = C = CH7?

Q 37.

Which of the following compounds will not exist as resonance hybrid? Give reason for your answer.

(a) CH3OH
(b) R-CONH2
(c) CH3CH = CHCH2NH2

Q 38.

By mistake, an alcohol (boiling point 97 °C) was mixed with a hydrocarbon (boiling point 68 °C). Suggest a suitable method to separate the two compounds. Explain the reason for your choice.

Q 39.

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

Q 40.

Explain the terms inductive and electromeric effects. Which electron displacement effect explain the following correct orders of acidity of the carboxylic acids?
(a) Cl3CCOOH > Cl2CHCOOH > ClCH2 COOH
(b) CH3CH2COOH > (CH3)2 CHCOOH > (CH3)3CCOOH

Q 41.

What is the difference between distillation, distillation under reduced pressure and steam distillation?

Q 42.

Discuss the chemistry of Lassaigne’s test.

Q 43.

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

Q 44.

How will you separate a mixture of two organic compounds which have different solubilities in the same solvent?

Q 45.

Name a suitable adsorbent used in the process of column chromatography.

Q 46.

Name three types of chromatography.

Q 47.

Which type of compounds are purified by steam distillation?

Q 48.

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

Q 49.

What is the basic principle of chromatography?

Q 50.

0.15 g of an organic compound gave 0.12 g of Ag Br by the Carius method. Find percentage of Br in the compound.