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Na2CO3 + Ca(OH)2 + Heat + Water = NaOH + CaCO3 + ?

  1. Nov 15, 2009 #1
    Na2CO3 + Ca(OH)2 + Heat + Water = NaOH + CaCO3 + ???

    This is an experiment I got from the golden book of chemistry experiements. It says you can mix Washing Soda (from the laundry products section) with water in a glass bowl, then heat it up a bit, then mix in Hydrated Lime Powder (from gardening stores), and it is supposed to create NaOH and CaCO3 which can be seperated with a filter. My friend wants me to make this experiment because he uses Lye and Calcium Carbonate for house hold applications.

    He was already making his NaOH from electrolyte with Salt but he doesn't enjoy dispensing of Chlorine Gaz and Hydrogen. And he can get all the products for this hydrated lime experiments from the same stores he frequents regularly. He would save money I think from finding a use for both products in the experiment's outcome.

    How violent would this experiment be? Other than playing with substances that are naturally dangerous from not having a neutral PH, are there any other dangerous sides to this? Gaz? Chances of explosion? Burns? How dangerous is this...

    Can you just expect a safe experiment as long as you don't drop all the solution on yourself? What about fumes? Are vapors toxic?

    And the experiment is said to be used with 50 ml of water, and doesn't even mention the portions for the slaked lime mixed with water... he wants to produce decent quantities, is this possible?

    also, how would he be able to make sure the liquid that goes through the filter is 100% naoh + water?
  2. jcsd
  3. Nov 16, 2009 #2


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    Staff: Mentor

    Re: Na2CO3 + Ca(OH)2 + Heat + Water = NaOH + CaCO3 + ???

    Only thing I can think of is that mixture may start to splash when heated - so you should be prepared for that. No toxic fumes/vapors - although concentrated NaOH solutions tend to liberate caustic aerozol, so either use fume hood or at least do the experiment outside. Other than that with small amounts of substances it shouldn't be dangerous, as long as you remember about glasses, apron and common reason.

    Scaling up can be problematic.
    Last edited by a moderator: Aug 13, 2013
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