BITSAT2013Chemistryp Block Elements (Group 15, 16, 17 & 18)Actual
Which of the following is less acidic among the given halogen compounds?
Options
- ACHF ₃
- BCH ₃
- CCHCl ₃
- DCHBr ₃
Correct answer
A. CHF ₃
Step-by-step solution
Due to stronger-I-effect of F than that of Cl, CHF ₃ should be more acidic than CHCl ₃ . But actually reverse is true. This is due to : CCl ₃⁻ left after the removal of a proton from CHCl ₃ is stabilised due to presence of d -orbitals in Cl than: CF ₃⁻ left after the removal of a proton from CHF ₃ which is not stabilised due to the absence of d -orbitals on F .