See image — GOC and Organic Chemistry Basics Chemistry Question

💡 Solution & Explanation

## Solution **Step 1: Identify the structures** - (a) But-3-en-1-ene (1-butene): $CH_2=CH-CH_2-CH_3$ — terminal double bond - (b) 2-methylpropene: $(CH_3)_2C=CH_2$ — disubstituted double bond - (c) Cyclobutene — ring with one double bond - (d) Cyclobutene (different conformation) — ring with one double bond **Step 2: Determine maximum stability** Alkene stability increases with substitution of the double bond: $$\text{Monosubstituted} < \text{Disubstituted} < \text{Trisubstituted} < \text{Tetrasubstituted}$$ Compound **(b)** has a disubstituted double bond (most substituted among acyclic alkenes), making it the **most stable**. **Step 3: Determine maximum heat of hydrogenation** Heat of hydrogenation reflects the energy released: more strained/less stable alkenes release more heat. Cyclobutene **(c)** and **(d)** have ring strain from the 4-membered ring, making them less stable and more exothermic upon hydrogenation. Between (c) and (d), they are the same compound, so **(c)** has the **maximum heat of hydrogenation**. **Step 4: Select the pair** - 1st compound (maximum stability): **(b)** - 2nd compound (maximum heat of hydrogenation): **(c)** **Answer: (a) b, c** ✓ The pair (b, c) satisfies both criteria — (b) is the most stable due to its disubstituted double bond, and (c) releases the most heat upon hydrogenation due to ring strain.