# Primitive Technology - Production of NaOH

We need to produce NaOH with primitive Technology. This is Part 1 of my Gilligan's Island Challenge series (Part 2). You are stuck on an island with access to a beach, a forest, a river, a lake, and a surface vein of coal.

I realize it can be made from $$\ce{NaHCO3 + Ca(OH)2}$$, and a person in a primitive technology scenario would be able to make some soda ash, but is there another way? $$\ce{NaHCO3}$$ might be tough to acquire in substantial quantities without access to a trona mine.

Would adding $$\ce{NaCl}$$ to a highly basic solution of, say, lime cause $$\ce{NaOH}$$ to form? If so, could it be extracted? Assume electricity is hard to come by.

• No. Why would it? CaCl2 is soluble just fine, hence no reaction. – Ivan Neretin Sep 5 '19 at 20:54
• How about sodium sulfate instead of NaCl? The wikipedia article on it shows it occurs naturally at various locations. – Ed V Sep 5 '19 at 22:27
• Ca(OH) 2 would be pretty easy to make, could that be substituted? – blacksmith37 Sep 6 '19 at 0:15
• I like this Gilligan's Island Challenge! This is an important question: without lye, there would be no lutefisk or hominy! Lye, especially KOH, but also some NaOH, was traditionally obtained by leaching wood ashes. As stated in wiki (en.wikipedia.org/wiki/Lutefisk), birch ash "contains high amounts of potassium carbonate and bicarbonate". – Ed V Sep 6 '19 at 0:25
• @EdV - Wow! That is exactly the answer I was looking for. – R Dev Sep 6 '19 at 11:35