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### Topic: Saturating a solution with sodium bicarbonate  (Read 430 times)

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#### Aymeric

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##### Saturating a solution with sodium bicarbonate
« on: December 05, 2020, 02:19:56 PM »
Hello,

I’m not sure where this question best fits, sorry if this is the wrong sub-forum.

I’m a complete amateur and have very basic knowledge of chemistry. I would like to saturate a liquid solution consisting of almost only water, with sodium bicarbonate.
I have no idea how to go about calculating the maximum amount of sodium bicarbonate I can dissolve into this solution to saturation, without having too much residue clumping up at the bottom.

PS. This is not homework, just a personal project.

#### Corribus

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##### Re: Saturating a solution with sodium bicarbonate
« Reply #1 on: December 05, 2020, 03:41:48 PM »
You can look up the solubility of sodium bicarbonate, although that relies on assumption of standardized conditions.  Better to just dissolve until saturation and then filter.
What men are poets who can speak of Jupiter if he were like a man, but if he is an immense spinning sphere of methane and ammonia must be silent?  - Richard P. Feynman

#### Aymeric

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##### Re: Saturating a solution with sodium bicarbonate
« Reply #2 on: December 06, 2020, 07:47:25 AM »
Thank you Corribus. I’ve tried adding a little less than the solubility (87 g/L, so I added 8g to a 100 mL solution), I mixed for several minutes at high speed, and a few hours later about half of the bicarbonate sodium is clumped up at the bottom of my vial

#### AWK

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##### Re: Saturating a solution with sodium bicarbonate
« Reply #3 on: December 06, 2020, 08:31:28 AM »
It is not known why you need a saturated solution of NaHCO3. But to obtain such a solution is quite a challenge. Typically, solutions are simply heated to speed up dissolution. In the case of sodium bicarbonate, this method is useless because already at 40°C the compound begins to slowly decompose thermally and around 80 degrees the decomposition is very fast. In addition, NaHCO3 dissolves extremely slowly in water. The chemist should be patient. A week of intense mixing will probably be enough.
AWK

#### Aymeric

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##### Re: Saturating a solution with sodium bicarbonate
« Reply #4 on: December 06, 2020, 08:46:48 AM »
It is not known why you need a saturated solution of NaHCO3. But to obtain such a solution is quite a challenge. Typically, solutions are simply heated to speed up dissolution. In the case of sodium bicarbonate, this method is useless because already at 40°C the compound begins to slowly decompose thermally and around 80 degrees the decomposition is very fast. In addition, NaHCO3 dissolves extremely slowly in water. The chemist should be patient. A week of intense mixing will probably be enough.
Thank you for the pointers! I’ll just be patient then