Exams › JEE Advanced › Chemistry

Consider two statements. Statement I: The presence of the weaker pi bond makes alkenes less stable (more reactive) than alkanes. Statement II: The strength of a carbon-carbon double bond is greater than that of a carbon-carbon single bond. Choose the correct option.

1. Both Statement I and Statement II are correct.
2. Both Statement I and Statement II are incorrect.
3. Statement I is correct but Statement II is incorrect.
4. Statement I is incorrect but Statement II is correct.

Correct answer: Both Statement I and Statement II are correct.

Solution

An alkene's C=C contains a sigma and a pi bond. The pi bond is weaker and exposed, making alkenes more reactive (less kinetically inert) than alkanes - Statement I is correct. However the overall double bond energy is greater than a single bond because it has two components; a C=C bond (~611 kJ/mol) is stronger than a C-C bond (~347 kJ/mol), though not twice as strong - Statement II is correct. The pi bond being weaker than the sigma bond is consistent with both statements.

Related JEE Advanced Chemistry questions

• When N₂ is converted to N₂⁺, what happens to the bond dissociation energy of the N–N bond, and when O₂ is converted to O₂⁺, what happens to the bond dissociation energy of the O–O bond?
• In which of these ions is pπ–dπ bonding absent?
• What is the VSEPR formula for the chlorine trifluoride molecule?
• Consider the following molecules: CO2, SO2, and H2O. Arrange them in ascending order of their dipole moments.
• Which of the following occurrences is primarily influenced by hydrogen bonding?
• When two 1s atomic orbitals (one from each atom) combine to form molecular orbitals, which of the following statements is correct?

⚔️ Practice JEE Advanced Chemistry free + battle 1v1 →