Distilled water with a pH of 7 is considered which classification?

• A. Salt
• B. Neutral
• C. An acid
• D. An alkali

Answer: (B)

Understanding how the pH scale classifies liquids is what this item tests. A pH of seven sits right in the middle, meaning the substance is neither acidic nor basic. Distilled water is considered neutral because it has no dissolved minerals or salts that would alter its hydrogen ion concentration, so its pH is typically around 7 at standard room conditions. On the scale, acids have a pH below seven and alkalis (bases) have a pH above seven. Salt itself isn’t a pH category. Therefore, distilled water with a pH of 7 is classified as neutral. Keep in mind that if carbon dioxide from the air dissolves into water, it can form a weak acid and nudge the pH slightly below seven, but in standard teaching it’s treated as neutral.