Arrange the following in decreasing order of basic strength (I) CH 3 CH 2 MgBr (II) H - C ≡ CMgBr (III) CH 3 CH 2 OMgBr

Question

Arrange the following in decreasing order of basic strength (I) CH 3 CH 2 MgBr (II) H - C ≡ CMgBr (III) CH 3 CH 2 OMgBr (A) I, III and II (B) II, I and III (C) III, II and I (D) I, II and III

Tardigrade Admin · Accepted Answer

The best way to compare their basic strength is to compare the acidic strength of their conjugate acid and then reverse the order because there is inverse relation in the strength of conjugate pair. The order of acidic strength of conjugate acid is

C H_{3} C H_{2} O H < H - C \equiv C - H > C H_{3} C H_{3}

∴

Decreasing order of basic strength is

C H_{3} C H_{2}^{-} > H - C \equiv C^{-} > C H_{3} C H_{2} O^{-}

Q. Arrange the following in decreasing order of basic strength (I) CH3​CH2​MgBr (II) H−C≡CMgBr (III) CH3​CH2​OMgBr

I, III and II

II, I and III

III, II and I

I, II and III

Q. Arrange the following in decreasing order of basic strength
(I) $C H_{3} C H_{2} M g B r$
(II) $H - C \equiv CM g B r$
(III) $C H_{3} C H_{2} OM g B r$