Question

How does salt change the pH of water?

Answer 1

NaCl is a salt of a strong acid and strong base. As you know, strong acids give weak conjugate bases and strong bases give weak conjugate acids. Hence, the Cl− ions are too weak to accept protons from water and Na+ ions are to weak to react with OH−. So there is no change in the concentration of H+ or OH−, so no change in pH.

But of a salt like CH3COONa is added, CH3COO− accepts protons and changes pH. This is because, weak acid CH3COOH gives strong conjugate base CH3COO