What is the correct order of reactivity of haloalkanes towards β...

The reactivity of haloalkanes towards $\beta$-elimination reactions depends on the stability of the alkene formed as the product.

According to Saytzeff's rule, highly substituted alkenes are more stable due to a greater number of hyperconjugative structures.

Tertiary (3^{}^{\circ}) haloalkanes yield more substituted alkenes compared to secondary (2^{}^{\circ}) and primary (1^{}^{\circ}$) haloalkanes. Furthermore, the transition state in the elimination reaction is stabilized by the electron-donating inductive effect and hyperconjugation of the attached alkyl groups.<br><br>Therefore, the correct order of reactivity towards \beta$-elimination is 3^{}^{\circ} > 2^{}^{\circ} > 1^{}^{\circ}.

Answer: 3^{}^{\circ} > 2^{}^{\circ} > 1^{}^{\circ}