Class 11th

This is a Multiple Choice Questions as classified in NCERT Exemplar

42. Option (i) II > I > III is correct since in case (I), positively charged C is attached to two alkyl groups and is stabilized through  +I effect. In case (II), +R effect of - OCH3group stabilizes this carbocation. In case (III), - I effect of - OCH3 group destabilizes the carbocation.

Hence, the order of stability is given as: 

II > I >III.

This is a Multiple Choice Questions as classified in NCERT Exemplar

41. Option (ii) Partition is correct since partition chromatography is based on the principle of continuous differential partitioning of components of a mixture between a stationary and a mobile phase. Paper chromatography is a type of partition chromatography only.

This is a Multiple Choice Questions as classified in NCERT Exemplar

40. Option (iv)

Thin layer chromatography is correct since thin layer chromatography is a method for analysing the mixtures by separating the components of the mixture. This technique can be used to determine the number of components in a mixture, the identity of compounds and the purity of compounds by observing the appearance of a product or the disappearance of a reactant. It can also be used to analyse the progress of a reaction. 

This is a Multiple Choice Questions as classified in NCERT Exemplar

39. Option (iv)

Steam distillation is correct since this technique is applicable to separate the substances which are steam volatile and are immiscible with water. In steam distillation, steam from a generator is passed through a heated flask containing the liquid to be distilled. The mixture of steam and the volatile organic compound is then condensed and is collected. The compound is later separated from water using the separating funnel.

This is a Multiple Choice Questions as classified in NCERT Exemplar

38. Option (iii)

Alkyl halides is correct since functional isomers are the ones which have the same molecular formula but different functional groups being present in them. 

Alcohols are functional isomers of ethers while aldehydes are the functional isomers of ketones whereas cyanides are functional isomers of isocyanides.  Only alkyl halides are the ones which do not show functional isomerism.

This is a Multiple Choice Questions as classified in NCERT Exemplar

37. Option

(iii) CH₃ - CH₂ - C ≡ *CH is correct since electronegativity of carbon depends on its hybridized state and percentage of s-character. Electronegativity ∝ percentage of  s-character.

So, the order of percentage 's' character is given as-

 sp³ (25%) < sp² (33%) < sp (50%)

In option (iii) Carbon linked through triple bond and is sp hybridized hence it is highly electronegative.

This is a Multiple Choice Questions as classified in NCERT Exemplar

36. Option (ii) 1-Chloro-4-methyl-2-nitrobenzene is correct since the substituent of the base compound is given number 1 and then the direction of numbering is chosen in such a manner that the next substituent gets the lowest number. The substituents that appear in the IUPAC name are in alphabetical order.  Hence in this case numbering can be shown as-

This is a Multiple Choice Questions as classified in NCERT Exemplar

35. Option (iv) 4-oxopentanoic acid is correct  since more than one functional group is present in the chain so, out of the two functional groups one will be given more priority as a result numbering is done from that side and mentioned as a sec. suffix, while the other one is written as prefix and mentioned as oxo along with the locant.

This is a Multiple Choice Questions as classified in NCERT Exemplar

34. Option (i) 3-Ethyl-4, 4-dimethylheptane is correct since in IUPAC naming the different alkyl groups present are written in alphabetical order. Di, tri, tetra are not included in the alphabetical order. So, “e” of the ethyl group comes before the “m” of the dimethyl group. The number 3 is given to the ethyl group and is written first.