pH

Do you know why lemonade tastes sour or why soap feels slippery? The answer lies in pH, which stands for “potential of hydrogen.” It is a scientific scale ranging from 0 to 14 with no units.

Substances with a pH below 7 are acids; those above 7 are bases. A pH of 7 is neutral.

Acids like lemon juice have pH values around 2 or 3 and taste sour. When dissolved in water, they release hydrogen ions. The more hydrogen ions, the stronger the acid.

In contrast, bases, like soap, feel slippery and taste bitter. When dissolved in water, they release hydroxide ions. When an acid and base are added together, the hydrogen and hydroxide ions neutralize each other, forming water molecules.

There are also neutral substances, like pure water, which have a perfect balance of hydrogen and hydroxide ions.

To identify the pH of solutions, we can use the pH paper, which changes color based on whether the solution is acidic or basic. We can also use digital pH meters, which give more accurate pH values.