Editing Sodium hydroxide (section)

===Esterification and transesterification reagent===
Sodium hydroxide is traditionally used in soap making ([[cold process]] soap, [[saponification]]).<ref name="Morfit">{{cite book|title =A treatise on chemistry applied to the manufacture of soap and candles|first= Campbell|last=Morfit|author-link=Campbell Morfit|publisher=Parry and McMillan|year = 1856|url =https://archive.org/details/atreatiseonchem00morfgoog}}</ref> It was made in the nineteenth century for a hard surface rather than liquid product because it was easier to store and transport.

For the manufacture of [[biodiesel]], sodium hydroxide is used as a [[catalyst]] for the [[transesterification]] of methanol and triglycerides. This only works with [[anhydrous]] sodium hydroxide, because combined with water the fat would turn into [[soap]], which would be tainted with [[methanol]]. NaOH is used more often than [[potassium hydroxide]] because it is cheaper and a smaller quantity is needed. Due to production costs, NaOH, which is produced using common salt is cheaper than potassium hydroxide.<ref>{{cite web|title=Side by Side Comparison: Potassium Hydroxide and Sodium Hydroxide - Similarities, Differences and Use Cases|url=https://info.noahtech.com/blog/sicomparison-potassium-hydroxide-and-sodium-hydroxide|access-date=2020-10-03|website=info.noahtech.com|language=en-us|archive-date=2020-10-10|archive-url=https://web.archive.org/web/20201010090833/https://info.noahtech.com/blog/sicomparison-potassium-hydroxide-and-sodium-hydroxide|url-status=dead}}</ref>