Some pairs of ions are given below. In which pair, first ion is more stable than second ion ?

Question

Some pairs of ions are given below. In which pair, first ion is more stable than second ion ? (A) H 3 C - overset⊕C H - CH 3 and - overset⊕C H - ddot O CH 3 (B) H3C - CH2 - overset ⊕ C H - CH3 and H2C - CH2 - CH - overset ⊕ CH2 (C)  (D)

Tardigrade Admin · Accepted Answer

For carb-cations: (i) order of stability =3°>2°>1° . (ii) (+) ve carbon centre in conjugation is more stable. iii) Substituted carbcations is more stable. Thus, option (a) is the correct choice.

Q. Some pairs of ions are given below. In which pair, first ion is more stable than second ion ?

$H_{3} C - C \oplus H - C H_{3}$ and $- C \oplus H - \ddot{O} C H_{3}$

$H_{3} C - C H_{2} - C \oplus H - C H_{3}$ and $H_{2} C - C H_{2} - C H - C \oplus H_{2}$

For carb-cations :

(i) order of stability $= 3^{\circ} > 2^{\circ} > 1^{\circ} .$

(ii) (+) ve carbon centre in conjugation is more stable.

iii) Substituted carbcations is more stable. Thus, option (a) is the correct choice.

Q. Some pairs of ions are given below. In which pair, first ion is more stable than second ion ?

H3​C−C⊕H−CH3​ and −C⊕H−O¨CH3​

H3​C−CH2​−C⊕H−CH3​ and H2​C−CH2​−CH−C⊕H2​

For carb-cations : (i) order of stability =3∘>2∘>1∘. (ii) (+) ve carbon centre in conjugation is more stable. iii) Substituted carbcations is more stable. Thus, option (a) is the correct choice.

$H_{3} C - C \oplus H - C H_{3}$ and $- C \oplus H - \ddot{O} C H_{3}$

$H_{3} C - C H_{2} - C \oplus H - C H_{3}$ and $H_{2} C - C H_{2} - C H - C \oplus H_{2}$

For carb-cations :

(i) order of stability $= 3^{\circ} > 2^{\circ} > 1^{\circ} .$

(ii) (+) ve carbon centre in conjugation is more stable.

iii) Substituted carbcations is more stable. Thus, option (a) is the correct choice.