Question
IUPAC name of the some alkenes are given below. Find out the correct stability order. A. 2-Methylbut-2-ene B. cis-But-2-ene C. 2,3-Dimethylbut-2-ene D. Prop-1-ene Choose the correct answer from the options given below :
JEE Main
Chemistry
Hydrocarbons
2026
JEE Main 2026 (05 April Shift 2)
JEE Main Chemistry Question (2026) — Solution
Options
- A. C > A > B > D
- B. C > A > D > B
- C. B > D > A > C
- D. A > B > C > D
Answer
A. C > A > B > D
Step-by-step solution
The stability of alkenes is directly proportional to the number of -hydrogen atoms due to hyperconjugation. Let us count the number of -hydrogen atoms in each given alkene: A. 2-Methylbut-2-ene: (CH_3)_2C=CHCH_3 Number of -hydrogen atoms = 3 + 3 + 3 = 9 B. cis-But-2-ene: CH_3CH=CHCH_3 Number of -hydrogen atoms = 3 + 3 = 6 C. 2,3-Dimethylbut-2-ene: (CH_3)_2C=C(CH_3)_2 Number of -hydrogen atoms = 3 + 3 + 3 + 3 = 12 D. Prop-1-ene: CH_3CH=CH_2 Number of -hydrogen atoms = 3 Since the stability of an alkene increases with the number of -hydrogen atoms, the correct stability order is C > A > B > D. Answer: C > A > B > D
Related: Chemistry — Hydrocarbons · All PYQ Banks