What is the hybridization of each carbon in H7C = C = CH7?
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
Name a suitable technique of separation of the components from a mixture of calcium sulphate and camphor.
What are electrophiles? Explain electrophile substitution reaction with the help of example.
The IUPAC name for
(a) 1-Hydroxypentane-l, 4-dione
(b) 1,4-Dioxopentanol
(c) l-Carboxybutan-3-one
(d) 4-Oxopentanoic acid
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 .
(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?
Compounds with same molecular formula but differing in their structures are said to be structural isomers. What type of structural isomerism is shown by
Describe the method, which can be used to separate two compounds with different solubilities in a solvent S.
Why is it necessary to use acetic acid and not sulphric acid for acidification of sodium extract for testing sulphur by lead acetate test?
(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
Resonance structures of propenal are given below. Which of these resonating structures is more stable? Give reason for your answer.
(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?
Electronegativity of carbon atoms depends upon their state of hybridization. In which of the following compounds, the carbon marked with asterisk is most electronegative?
In which of the following compounds the carbon marked with asterisk is expected to have greatest positive charge?
Ionic species are stabilized by the dispersal of charge. Which of the following carboxylate ions is the most stable?
Write the structures of various carbocations that can be obtained from 2-methylbutane. Arrange these carbocations. in order of increasing stability.
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 |
What are hybridisation states of each carbon atom in the following compounds? CH2=C=O, CH3CH=CH2, (CH3)2CO, CH2=CHCN, C6H6.
How will you separate a mixture of two organic compounds which have different solubilities in the same solvent?
If a liquid compound decomposes at its boiling point, which method(s) will you choose for its purification? It is known that the compound is stable at low pressure, steam volatile and insoluble in water.
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
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 |
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.
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
Differentiate between the principle of estimation of nitrogen in an organic compound by (i) Dumas method (ii) Kjeldahl’s method.
Discuss the principle of estimation of halogens, sulphur and phosphorus present in an organic compound.
Explain the reason for the fusion of an organic compound with metallic sodium for testing nitrogen, sulphur and halogens.
Suggest a suitable technique for separating naphthalene from kerosene oil present in a mixture.
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
Covalent bonds can undergo fission in two different ways. The correct representation involving the heterolytic fission of CH3 – Br is
Which of the following compounds contain all the carbon atoms in the same hybridization state?
Why is a solution of potassium hydroxide used to absorb carbon dioxide evolved during the estimation of carbon present in an organic compound?
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.
Write the name of element which is confirmed on adding Na2[Fe(CN)5NO] in sodium extract solution due to appearance of violet colouration.
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.
