Chemistry

Organic Chemistry

Question:

Match the type of mixture of compounds in Column I with the technique of separation/purification given in column II.

Column I Column II
(a) Two solids which have different solubilities in a solvent and which do not undergo reaction when dissolved in it. (1) Steam distillation
(b) Liquid that decomposes at its boiling point (2) Fractional distillation
(c) Steam volatile liquid (3) Simple distillation
(d) Two liquids which have boiling points close to each other (4) Distillation under reduced pressure
(e) Two liquids with large difference in boiling points. (5) Crystallisation

Answer:

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

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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.

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 4.

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 5.

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

Q 6.

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 7.

Which gas is liberated in Kjeldhal’s method?

Q 8.

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 9.

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

Q 10.

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

Q 11.

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

Q 12.

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 13.

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 14.

Identify the pairs of compounds which are functional group isomers.

Q 15.

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 16.

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 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.

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

Q 19.

Identify the pairs of compounds that represent position isomerism.

Q 20.

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 21.

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

Q 22.

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 23.

Which type of compounds are purified by steam distillation?

Q 24.

What is the basic principle of chromatography?

Q 25.

(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 26.

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 27.

What are electrophiles and nucleophiles? Explain with examples:

Q 28.

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 29.

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

Q 30.

Name three types of chromatography.

Q 31.

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.

Q 32.

(a) What is the basic principle involved in the estimation of nitrogen by Dumas method.
(b) In a Dumas nitrogen estimation method, 0.30 g of an organic compound gave 50 cm3 of N2 collected at 300 K and 715 mm Hg pressure. Calculate the percentage composition of nitrogen in the compound. (Vapour pressure of water at 300 K is 15 mm Hg)

Q 33.

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 34.

In DNA and RNA, nitrogen atom is present in the ring system. Can Kjeldahl method be used for the estimation of nitrogen present in these? Give reasons.

Q 35.

Identify the most stable species in the following set of ions giving reasons:
ncert-exemplar-problems-class-11-chemistry-chapter-12-organic-chemistry-some-basic-principles-42
 

Q 36.

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

Q 37.

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

Q 38.

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

Q 39.

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

Q 40.

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

Q 41.

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

Q 42.

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 43.

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 44.

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 45.

Which of the above compounds form pairs of metamers?

Q 46.

Identify the pairs of compounds that represent chain isomerism.

Q 47.

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 48.

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

Q 49.

Explain why alkyl groups act as electron donors when attached to a π-system.

Q 50.

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