Talk:Saltwater soap

Why normal soap cannot be used in sea water?
Original sentence (in the 1st paragraph): Normal fresh water soap will not lather or dissolve in salt water due to high levels of sodium chloride in the water.

In Hong Kong, the chemistry textbooks say that sea water is a kind of hard water. It contains a (relatively) high levels of calcium ions (Ca2+) and magnesium ions (Mg2+). When normal soap is dissolved in water, Ca2+ and Mg2+ form scums with the soap-molecule tail (which is an anion) and reduce the effectiveness of soap and make the clothes dirty.

Also, although the level of sodium ions (in form of NaCl) is high in sea water, it is just about 3.5% in average which is far away from being saturated.

So, is this related to high levels of sodium ions, or (relatively) high levels of calcium ions and magnesium ions?

116.48.138.238 (talk) 05:28, 5 August 2015 (UTC)

It is difficult to get a soap lather in hard water or in salt water (possibly because, as you point out, seawater is a type of hard water). I've asked for sources for the original definition "saltwater" or "sailor" soap and the relevance of the hydroxide used because this information is not sourced.Ebbn (talk) 19:51, 18 January 2019 (UTC)