The less carbon in a monoacid molecule, the stronger the acidity, such as formic acid >: acetic acid >: propionic acid. . . Binary acids are generally more acidic than monobasic acids, such as oxalic acid; Formic acid. . . Aromatic acids are generally more acidic than organic fatty acids containing carboxyl groups in the same carbon series, such as benzoic acid >: formic acid. The molecule contains another electron-withdrawing group, such as fluoroacetic acid >: acetic acid; Trinitrobenzoic acid > benzoic acid. . .