A salt formed by an acid-base reaction gives an acidic solution. What does this indicate about the parent substances?

Correct answer: The acid may be strong and the base weak

Salt hydrolysis explains the observation. A salt produced from a strong acid and a weak base commonly gives an acidic aqueous solution because its positive ion hydrolyses water and increases hydrogen-ion concentration. Thus option A is the best conclusion, although the wording “may be” is important because solution behaviour also depends on relative strengths and concentration. Strong acid–strong base salts are generally neutral.