Neutralization titration for pure soluble salt synthesis

Steps:

• Identify KCl as the target: a soluble salt from K+ and Cl- ions.
• Select reactants: KOH(aq) provides K+, HCl(aq) provides Cl- and H+ for reaction.
• Perform titration: add HCl to KOH using indicator to reach equivalence point, ensuring KOH + HCl → KCl(aq) + H2O with no excess.
• Isolate pure KCl: evaporate the neutral solution to crystallize solid KCl.

Why D is correct:

• Titration ensures stoichiometric neutralization (KOH + HCl → KCl + H2O), yielding pure KCl(aq) free of impurities, per acid-base reaction principles.

Why the others are wrong:

• A: No reaction occurs; AgCl(s) is insoluble and unaffected by KNO3(aq).
• B: AgCl is not aqueous (sparingly soluble); mixing yields no KCl.
• C: Mixing without titration risks excess KOH or HCl, contaminating KCl.

Final answer: D