Stability ranking of drawn radicals, carbanions and carbenes

14 questions on Stability ranking of drawn radicals, carbanions and carbenes from the General Organic Chemistry III: Reaction Intermediates chapter: 3 NEET level, 7 JEE Main, 4 JEE Advanced. Each one opens with its answer and solution.

• A bromine atom abstracts one hydrogen atom from the compound shown. Which radical shown is formed preferentially? NEET level, drawn structure
• The compound shown is treated with a strong base, which removes one proton from a carbon atom. Among the carbanions shown, which one is the most stable and is t... NEET level, drawn structure
• The compound shown is treated with concentrated aqueous KOH. After deprotonation, loss of chloride from the trichloromethyl anion gives a neutral reactive inter... NEET level, drawn structure
• A bromine atom abstracts one hydrogen atom from the compound shown. Which radical shown is formed most readily? JEE Main level, drawn structure
• The compound shown is treated with a base and loses one proton from carbon. Which carbanion shown is the most stable? JEE Main level, drawn structure
• The singlet carbene shown is much more stable than singlet methylene. What is the main reason? JEE Main level, drawn structure
• Which of the carbanions shown is the most stable? (The hydrocarbon shown is the parent of one of them.) JEE Main level, drawn structure
• Which statement about the ground state of the species shown is correct? JEE Main level, drawn structure
• Which statements about the radical shown are correct? Select all that apply. JEE Main level, drawn structure
• Deprotonation at the unique C-H of the cation shown with a strong base gives a neutral species. Which description of this species is correct? JEE Main level, drawn structure
• Cyclopentadiene (pKa about 16) is a far stronger carbon acid than the compound shown (pKa about 36). Which explanation is correct? JEE Advanced level, drawn structure
• A bromine atom abstracts one hydrogen atom from the compound shown. Which radical shown is the most stable one that can form? JEE Advanced level, drawn structure
• Cyclopentadiene is the compound shown. Which statements are correct? Select all that apply. JEE Advanced level, drawn structure
• Which statements about the singlet carbene shown are correct? Select all that apply. JEE Advanced level, drawn structure