Which of the following presents the correct order of the acidity in the given compounds?
FCH2COOH>ClCH2COOH>BrCH2COOH>CH3COOH
Acetic acid is the least acidic because there are no electronegative substituents at the α position. The presence of such an electronegative substituent tends to stabilize the negative charge present in the conjugate base of the given acids (via -I effect). Hence the increasing order of acidic strength is:
FCH2COOH>ClCH2COOH>BrCH2COOH>CH3COOH