Question

What is the pH of normal rainwater?

Answer 1

The $\mathrm{pH}$ of normal rainwater

• Rainwater has a $\mathrm{pH}$ of roughly $5.0$, which is a somewhat acidic state by nature. In volcanic regions, such as Hawaii, the $\mathrm{pH}$ of rain can range from $4.5$ to $5.0$ and Pure water has a pH of $7.0$.
• Rainwater has atmospheric carbon dioxide dissolved in it. Water and carbon dioxide combine to generate carbonic acid. Because it creates hydronium ions, or ${\mathrm{H}}_3{\mathrm{O}}^{+}$, when it interacts with water, carbonic acid is an acid.

Therefore, regular rain has a mild acidic flavor.