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.

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

Q 3.

Which type of compounds are purified by steam distillation?

Q 4.

What are electrophiles and nucleophiles? Explain with examples:

Q 5.

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

Q 6.

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 7.

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 8.

Which gas is liberated in Kjeldhal’s method?

Q 9.

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

Q 10.

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 11.

Give the TUPAC names of the following compounds:

cbse-class-11th-chemistry-organic-chemistry-basic-principles-techniques-4

Q 12.

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

Q 13.

Arrange the following in increasing order of C—C bond length:  C2H & C2H4, C2H2.

Q 14.

Name three types of chromatography.

Q 15.

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

Q 16.

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 17.

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 18.

How will you separate a mixture of Iodine and sodium chloride!

Q 19.

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 20.

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 21.

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

Q 22.

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

Q 23.

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 24.

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 25.

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

Q 26.

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 27.

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 28.

(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 29.

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

Q 30.

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

Q 31.

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 32.

Identify the pairs of compounds which are functional group isomers.

Q 33.

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 34.

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 35.

Discuss the chemistry of Lassaigne’s test.

Q 36.

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

Q 37.

What type of solids are separated by fractional crystallisation?

Q 38.

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 39.

What is the basic principle of chromatography?

Q 40.

(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 41.

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 42.

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 43.

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 44.

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 45.

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 46.

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

Q 47.

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

Q 48.

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

Q 49.

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

Q 50.

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