When soap is used in hard water, it forms a solid substance known as scum.
A chemical reaction can occur when two materials are combined. The atoms and molecules of the different substances interact and generate new substances. For instance, when two liquids are blended and solidified, a precipitate is the solid formed as a result. The interaction between dissolved soap and "hard" water is a well-known example of a precipitate-forming reaction. It is important to note here that the difference in the product (scum in hard water and lather in soft water) is because of the difference in the chemical properties of hard water. So, what is this hard water anyway? And which property of hard water is responsible for scum formation? Let's find out.
Water becomes briefly hard attributed to the prevalence of magnesium and calcium carbonates. The hardness in the water can be eliminated in this scenario by boiling it.
Permanent hardness is defined as the presence of soluble magnesium and calcium salts in the form of chlorides and sulfides in water, which cannot be eliminated by boiling.
Soap scum, sometimes known as lime soap, is a white substance of calcium stearate, magnesium stearate, and other alkali metal fatty acid derivatives.
1. How is soap scum formed?
When hard water and soap are combined, the magnesium ion combines with the soap molecules to generate a solid precipitate that does not dissolve. This precipitation of soap scum inhibits the soap's ability to produce bubbles.
2. What is soap scum?
Soap scum, sometimes known as lime soap, is a white substance of calcium stearate, magnesium stearate, and other alkali metal fatty acid derivatives. The introduction of soap, as well as other anionic surfactants to hard water, produces these compounds.
3. What pH is soap scum?
Soap scum is a coating that tends to be on the alkaline side of the pH scale (from eight to 14).
4. How does citric acid remove soap scum?
Citric acid softens hard water, adjusts pH levels, and improves the performance of detergent soap.
We hope you enjoyed studying this lesson and learned something cool about Soap Scum Formation! Join our Discord community to get any questions you may have answered and to engage with other students just like you! Don't forget to download our app to experience our fun VR classrooms - we promise it makes studying much more fun! 😎