A solution with pH less than 7 is called acid.

A solution with pH less than 7 is called acid.

• A. Alkaline
• B. Base
• C. Neutral
• D. Acid

Answer: (D)

The main idea is how pH relates to acidity. A solution with pH less than 7 has a higher concentration of hydrogen ions, which makes it acidic. An acid is defined as a substance that increases hydrogen ion concentration in water, yielding a pH below 7. Therefore, a solution with pH under 7 is called an acid. In contrast, alkaline or basic describes solutions with pH above 7, and neutral means the pH is exactly 7. This is why the statement is correct: low pH corresponds to acidity.

The main idea is how pH relates to acidity. A solution with pH less than 7 has a higher concentration of hydrogen ions, which makes it acidic. An acid is defined as a substance that increases hydrogen ion concentration in water, yielding a pH below 7. Therefore, a solution with pH under 7 is called an acid. In contrast, alkaline or basic describes solutions with pH above 7, and neutral means the pH is exactly 7. This is why the statement is correct: low pH corresponds to acidity.