71.

The decreasing order of acidic character among ethane (I), ethene (II), ethyne (III) and propyne (IV) is

• (I) > (II) > (III) > (IV)

• (II) > (III) > (I) > (IV)

• (III) > (IV) > (II) > (I)

• (IV) > (III) > (II) > (I)

The alkene that will give the same product with HBr in the absence as well as in the presence of peroxide is

• 2-butene

• 1-butene

• propene

• 2-methylpropene

Chlorination of benzene in the presence of halogen carrier is an example of

• aromatic nucleophilic substitution

• aromatic electrophilic substitution

• aromatic nucleophilic addition

• aromatic electrophilic addition

Two organic compounds X and Y on analysis gave the same percentage composition namely; C = (12/13) × 100% and H = (1/13) × 100%. However, compound X decolourises bromine water while compound Y does not. The two compounds X and Y may be respectively 

• acetylene and ethylene

• acetylene and benzene

• ethylene and benzene

• toluene and benzene

For preparing an alkane, a saturated solution of sodium or potassium salt of a carboxylic acid is subjected to

• hydrolysis

• electrolysis

• oxidation

• hydrogenation

The reaction of  with HBr gives predominantly

An organic compound with molecular formula C₆H₁₂ upon ozonolysis give only acetone as the product. The compound is

• 2,3-dimethyl-1-butene

• 3-hexane

• 2-hexene

• 2,3-dimethyl-2-butene

Which one of the following carbanions is the least stable?

• CH₃CH₂^-

• CH₃^-

• (CH₃)₃C^-

• HC≡C^-

An aromatic hydrocarbon with empirical formula C₅H₄ on treatment with concentrated H₂SO₄ gave a monosulphonic acid. 0.104 g of the acid required 10 mL of $\frac{\mathrm{N}}{20}$ NaOH for complete neutralisation. The molecular formula of hydrocarbon is 

• C₅H₄

• C₁₀H₈

• C₁₅H₁₂

• C₂₀H₁₆

An alkene having the molecular formula C₉H₁₈ on ozonolysis gives 2, 2-dimethyl propanal and 2-butanone. The alkene is :

• 2, 2, 2-trimethyl-3-hexene

• 2, 2, 6-trimethyl-3-hexane

• 2, 3, 4-trimethyl-2-hexene

• 2, 2, 4-trimethyl-3-hexene