Water Hardness and Soap Interaction

Flashcards covering key vocabulary related to water hardness and its interaction with soap.

Soft Water

Water that lathers easily with soap because it is free of dissolved salts.

Hard Water

Water that does not lather well with soap and may produce scum, often containing calcium ions.

Temporary Hardness

Hardness in water that is reversible by boiling, causing the precipitation of calcium carbonate.

Permanent Hardness

Hardness in water caused by soluble salts like gypsum, which does not precipitate with boiling.

Scum

The insoluble precipitate formed when soap reacts with calcium ions in hard water.

Calcium Carbonate

A substance found in limestone; when it reacts with carbon dioxide in rainwater, it forms soluble calcium hydrogen carbonate.

Limescale

Deposits formed from calcium carbonate in heating appliances and plumbing due to temporary hardness.

Sodium Stearate

A soap molecule with a hydrophobic tail and a hydrophilic end that can lift dirt and oil from surfaces.

Detergents

Synthetic cleaning agents that do not form scum with hard water and are made from sodium salts of sulphonates.

Calcium Ions

Positively charged calcium particles that contribute to water hardness and scum formation.