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I live in a small town where Potassium hydroxide is not readily available. (I need above for preparing liquid soap.) But Potassium chloride (KCl) and Quick Lime (CaO) are available as fertilizer and White-wash ingredients respectively. Can KOH be prepared from above ingredients? What will be reaction conditions?

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    $\begingroup$ Any crudely prepared KOH will pose a lot of problems. Calcium forms scum. $\endgroup$ – M. Farooq Jan 11 at 1:59
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Mixing $\ce{KCl + CaO}$, or $\ce{KCl + Ca(OH)2}$, will never produce pure $\ce{KOH}$ without $\ce{Ca(OH)2}$. And this Ca(OH)2 will prevent soap from being synthesized out of oil, as $\ce{(Ca(OH)2}$s destroy soap in case a little bit of soap has been synthesized. The only way of producing $\ce{KOH}$ out of $\ce{CaO}$ or $\ce{Ca(OH)2}$ is to mix it with potassium carbonate $\ce{K2CO3}$. Of course $\ce{Ca(OH)2}$ is not very soluble in water. But $\ce{CaCO3}$ is still more insoluble. So the following reaction is possible :$$\ce{Ca(OH)2 + K2CO3 -> 2 KOH + CaCO3(s)}$$ And the insoluble $\ce{CaCO3}$ can be filtrated to produce a KOH solution

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isn't potassium carbonate available as fertilizer? it's a lot more common. Then it would be a simple matter of mixing CaO with water and adding k2co3. Eventually you'd be left with solid caco3 and koh in solution

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    $\begingroup$ A big limitation with this method is calcium hydroxide is not readily soluble in water. You might get a gram or a few grams per liter into solution at thd start, but if you allow hydroxide ions to accumulate in the water then the solubility equilibrium shifts and the calcium hydroxide dissolution is choked off. $\endgroup$ – Oscar Lanzi Jan 11 at 2:43
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    $\begingroup$ historically potash lye was made by leaching the ash containing these two reactants, continously collecting the koh solution. Perhaps this works by preventing the equillibrium shift as hydroxide ions don't accumulate $\endgroup$ – Francis L. Jan 11 at 2:58

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