Organic chemistry-some basic principles and techniques practice · Mixed difficulty

Option B is correct because paper chromatography separates substances based on their partition coefficients between the stationary (water in the paper) and mobile phases.

Option A ($- \mathrm{N}{\mathrm{O}_2}$) is correct because the nitro group ($- \mathrm{N}{\mathrm{O}_2}$) has the strongest electron-withdrawing inductive effect due to the high electronegativity of both nitrogen and oxygen atoms.

Option D (Using separating funnel) is correct because oil and water are immiscible liquids, and a separating funnel allows for the easy separation of two such layers.

Option A (4,3,1) is correct because there are four structural isomers of primary amines, three of secondary amines, and one of tertiary amines with the formula C₄H₁₁N.

Option B (4) is correct because the ratio of sigma to pi bonds in benzene is 12:3, which simplifies to 4:1.

Option C (Both (a) and (b)) is correct because both silica gel and alumina are commonly used as adsorbents in Thin Layer Chromatography (TLC).

Option D (-OH) is correct because it exhibits +M effect due to lone pairs on oxygen and -I effect due to the high electronegativity of oxygen.

Option D (Carious method) is correct because the Carius method is specifically designed to quantitatively determine the amount of halogen present in an organic compound.

Option B (Ethyl-2-butenoate) is correct because it correctly identifies the ester functional group and the position of the double bond in the carbon chain.

Option A (0.84) is correct because the percentage of nitrogen is calculated using the formula involving the normality of the acid, its volume, and the weight of the food sample.

Option B (Ammonia) is correct because alkyl groups are electron-donating, increasing basicity, and ammonia has no alkyl groups.

Option C (The rate of nitration of benzene is greater than that of hexadeuterobenzene) is correct because the rate of nitration of benzene is almost the same as that of hexadeuterobenzene due to the slow electrophilic attack.

Option B is the correct IUPAC structure because it correctly represents 2,2-Dibromo-1-phenylpentane with the bromine atoms on the second carbon and the phenyl group on the first carbon of the pentane chain.

Option D (Phenanthrene) is correct because phenanthrene has more resonance structures compared to the other options, leading to higher resonance energy.

Option B (${CuO}$) is correct because copper(II) oxide is used to oxidize carbon to carbon dioxide and hydrogen to water in the detection of carbon and hydrogen in organic compounds.