Chemical Forums
Specialty Chemistry Forums => Citizen Chemist => Topic started by: alodg on August 13, 2016, 12:47:38 AM
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I just baked Sodium Bicarbonate to make Sodium Carbonate, but I need to be sure that I indeed have. The tolerance is between 400℉ - 450℉ (200℃ - 230℃) and I'm not sure I had the oven on high enough. I baked it for one hour, staring the powder half way.
What test can I perform to distinguish the two please?
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There are many methods, some of them may be performed in home:
1. Solubility of both compounds are quite different,
2. NaHCO3 does not form hydrates,
3. Na2CO3 change color of phenolphtalein, hydrogen carbonate usually change color to pale pink since small content od carbonate,
4. Titration.
And many others.
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There are many methods, some of them may be performed in home:
1. Solubility of both compounds are quite different,
2. NaHCO3 does not form hydrates,
3. Na2CO3 change color of phenolphtalein, hydrogen carbonate usually change color to pale pink since small content od carbonate,
4. Titration.
And many others.
Agreed.
I think elemental analysis also works very well
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Thank you for your replies.
I did notice some colour change, but didn't consider that t be enough of a uniform indicator of the change.
Not being a chemist I'm not sure how to try your fourth suggestion "Titration" and would like to know, with home appliances, what would be the simplest method to uniformly confirm the change please?
Thanks again, in advance.
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Sodium hydrogen carbonate start decomposing at ~60 C - solid, or ~40 C - in water solution. This is an equilibrium reaction and carbon dioxide is removed to atmosphere. After many hours of warming at these temperatures you can obtain almost pure sodium carbonate. But air contains some amount of carbon dioxide, and in this way you will never get absolutely pure sodium carbonate, even at higher temperatures. The only simple and quantitative way to determine contents of you sample is titration.
May first three suggestions can be used qualitatively. Just one of these is sufficient, and it depends on you home lab possibility, you invention, and your knowledge.
In the same way past great chemists worked. But the did not wait for precise procedure from others that solve their problems.
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I ain't no chemist mate. I'm just trying to make laundry powder.
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From GOOGLE
Arm & Hammer Super Washing Soda Detergent Booster & Household Cleaner, 55 oz $6.65
6.65 / 55 = 0.120909
ARM & HAMMER Pure Baking Soda 16 oz $0.75
0.75 / 16 = 0.046875
By the way
can we assume you have read
https://en.wikipedia.org/wiki/Sodium_bicarbonate (https://en.wikipedia.org/wiki/Sodium_bicarbonate)
and
https://en.wikipedia.org/wiki/Sodium_carbonate (https://en.wikipedia.org/wiki/Sodium_carbonate)
From WIKI
Thermal decomposition
Above 50 °C, sodium bicarbonate gradually decomposes into sodium carbonate, water and carbon dioxide. The conversion is fast at 200 °C:[12]
2 NaHCO3 :rarrow: Na2CO3 + H2O + CO2
Most bicarbonates undergo this dehydration reaction. Further heating converts the carbonate into the oxide (at over 850 °C):[12]
Na2CO3 :rarrow: Na2O + CO2
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Titration seems to be the easiest approach here, seeing how much of your solid is required to neutralize given amount of a strong acid.
See www.titrations.info for a general description of the titration itself, you need a variant of what is described in the acid-base section.