MCQ Detailed View

The pH value measures how acidic or basic a substance is. For water, the normal pH range is 6.5 to 8.5, which is slightly neutral to mildly basic depending on the source and dissolved minerals. Pure water ideally has a pH of 7, which is perfectly neutral.

The pH of water can change due to the presence of dissolved salts, carbon dioxide, or pollutants. For example, rainwater can be slightly acidic because it absorbs carbon dioxide from the air, forming carbonic acid. On the other hand, water in lakes or rivers with dissolved calcium or magnesium salts can be slightly basic.

Water’s pH is important for drinking, agriculture, and aquatic life. Most fish and plants grow well in water that is near neutral (pH 6.5–8.5). If the water is too acidic or too basic, it can harm aquatic life and affect its usability for humans.

Measuring water pH is also important in Chemistry, as it helps understand chemical reactions in solutions, water quality, and environmental studies. Water acts as a universal solvent, and its pH affects how chemicals dissolve, react, or neutralize.

So the correct answer is 6.5–8.5, which is the normal pH range of water suitable for drinking and supporting life.