Which acid of each pair shown here would you expect to be stronger?
CH2FCH2CH2CO2H or CH3CHFCH2CO2H
Inductive effect decreases with increase in distance(the more will be the distance of the inductive group from the carboxylic group less will be its effect of polarisability). Hence, the -I effect of F in CH3CHFCH2CO2H is more than it is in CH2FCH2CH2CO2H . Hence, CH3CHFCH2CO2H is a stronger acid than CH2FCH2CH2CO2H .