Vinegar (pH 3) and Soap/Bleach (pH 12/13) are in the opposite ends of the pH scale but are both used to clean surfaces effectively. Can someone explain why this is so?

Question

What is in vinegar that makes it clean well, and what is in soap/bleach that makes it clean well despite both being in opposite ends of the scale? And is it advisable to use one before the other for maximum effectiveness?

In: Chemistry

Answer 1

Yes, all of them are used for cleaning surfaces. But each of them are effective for very different types of stains and dirts.

Acidic cleaning agents – vinegar and citric acid target mineral deposits. They are often oxide, carbonate and sulfate salts that reacts with acids easily. So you will use them to clean limescale and tarnished metal surfaces.

Detergents – soaps have a distinct property where the same molecule is attracted by water and oil. So detergent molecules can pull greases into water, and be carried away once you rinse it.

Bleach and peroxides are really good at oxidizing (think as destroying) organic molecules. So they are used to kill microbes and decolour organic stains. But the same property also make them fairly corrosive on bare metal surfaces.