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Chemistry Forums for Students => Inorganic Chemistry Forum => Topic started by: 3rsaku on March 24, 2011, 02:25:37 PM

Title: Separate Sodium hydroxide and sodium carbonate in the solution
Post by: 3rsaku on March 24, 2011, 02:25:37 PM

As the title states, I have a batch reaction where the reactant sodium hydroxide is converted into sodium hydroxide as a byproduct. Since the reaction takes place in aqueous media and always there are some unreacted sodium hydroxide, how do i separate them both after the reaction? If there are many different ways to do this, could you guide me in the right direction. Thank you Chemical Forums.

Title: Re: Separate Sodium hydroxide and sodium carbonate in the solution
Post by: Nobby on March 28, 2011, 06:55:14 AM

You can add Calciumhydroxide and precipitate the carbonat as Calciumcarbonate, After filtering only NaOH is left

Title: Re: Separate Sodium hydroxide and sodium carbonate in the solution
Post by: 3rsaku on March 28, 2011, 08:05:32 AM

Thank you Nobby. The process you stated is very similar to recycling NaOH in Kraft process for pulping wood. I also read elsewhere from a non-reliable source that if I leave the mixture open to air (with CO2) for a while, the partial NaOH will be converted to sodium carbonate. P.S. Soda ash is the desired product.