Why is a solution of sodium chloride not pH-neutral? - Quora
Jul 03, 2015· A pure solution of sodium chloride is neutral, with a PH of seven, however, most water contains other ions, such as Fe3+, Ca2+ . et.al., The existence of these ions will react with water and then alter its PH. what? you are employing distilled water. even if you are start with distilled water (just like the answer of Eric Vene), gas in the air may also reacts with water and change its PH.