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### How to make %CO2 solution with Na2CO3 based on its stoichiometric relation & solubility?

Posted: Mon Dec 05, 2022 10:37 pm
Hi, I have a doubt about making an equivalent %co2 solution with sodium carbonate. I have attached the reference equation quoted in the research article. If anyone knows how to derive the equation kindly help me. How 1.3g/L of Na2CO3 came for 5% Co2 solution and help me to find out for 50% co2. I have doubt in this derivation.

***reference***

pH=6.30+log [ HCO3− ] −log [ CO2]

pH=10.09+log [ CO3 2- ] −log [ HCO3-]

The values of sodium carbonate concentrations corresponding to 5%, 10%, 15%, 20% and 30% CO2 concentrations at pH 7 are 1.3 g/L, 2.6 g/L, 3.8 g/L, 5.1 g/L, and 7.6 g/L, respectively.

****reference***

### Re: How to make %CO2 solution with Na2CO3 based on its stoichiometric relation & solubility?

Posted: Mon Dec 05, 2022 11:52 pm
1 mol Na2CO3 = 1 mol CO2

1,3 g /106 g/ mol = 0,012 mol Na2CO3 this correspond multiplied with 44 g/ mol to 0,528 g CO2 .
0,528g/1000 g = 0,000523
This solution is only 0,053%.
I think you have to dissolve 100 times more Na2CO3.
But the limit is 217 g/ l because of soloubility.
So 50 % is not possible.

### Re: How to make %CO2 solution with Na2CO3 based on its stoichiometric relation & solubility?

Posted: Tue Dec 06, 2022 1:28 am
Hai.... Thankyou so much for your immediate response...

As you said.... 1.3 g /106 g/ mol = 0.012 mol Na2CO3 this corresponds multiplied with 44 g/ mol to 0.528 g CO2 .

which means 0.528 g of CO2 in 1000ml since per liter is mentioned... is equivalent to 5g in 100ml.

But % solution means it always accounted for 100ml or 100g....means 5g in 100ml refers to 5% solution.

I manually calculated for % co2 solution with Na2co3 based on its mole equivalent [as per the research article reference I gave in the question]..which is shown below

Na2co3................Co2 equivalent
1.3g/L....................0.539 g/L
2.6g/L ...................1.079 g/L
3.8g/L....................1.577g/L
5.1g/L....................2.116g/L
7.6g/L....................3.154g/L

But 0.50 g/L is 5% solution......which is 5g in 100ml.....for this equivalent Na2Co3 is 1.2041 g/L....Mine calculation is shown below

Co2 equivalent......%CO2....Na2co3
0.50g/L..............5%.......1.2041 g/L
1.00g/L .............10%......2.4090 g/L
1.50g/L..............15%......3.6136 g/L
2.00g/L..............20%......4.8181 g/L
3.00g/L..............30%......7.2272 g/L

Na2Co3 concentration is not matching in both cases ( as per the reference article calculation & in my calculation)
My question here is why this mismatch is coming.... is there any calculation assumptions that needs to be considered or anything I missed...since in the reference article pH equation for CO2 solubility is given..is there anything to deal with the equation...(else they would have mentioned just by mole equality we calculated Na2co3 but they didn't)...

Article reference original file I could not able to attach here...*Sequestration of carbon dioxide and production of biomolecules using
cyanobacteria*
....this is the title of article..refer section 2.3 lethal dose analysis in this paper.
I kindly request you to solve my doubt...if you know...

### Re: How to make %CO2 solution with Na2CO3 based on its stoichiometric relation & solubility?

Posted: Tue Dec 06, 2022 2:39 am
which means 0.528 g of CO2 in 1000ml since per liter is mentioned... is equivalent to 5g in 100ml.
That is wrong.

You have 0,5 g in 1000 ml. Now you take 1/10 means 100 ml out of the Container then you have also 1/10 of mass what is 0,05g in 100ml and not 5g.
Or 0,5/1000 = 0,05/100 = 0,0005 or in percentage 0,5%.

### Re: How to make %CO2 solution with Na2CO3 based on its stoichiometric relation & solubility?

Posted: Tue Dec 06, 2022 2:49 am
ok sir...sorry now i understood my mistake....I don't know in that research article they equated it (0.529 g/L as 5% Co2 solution)....don't know how it came...Kindly refer that article I mentioned above
Kindly help me in this...is there anything to do with this pH equation. please help me

*****************
pH=6.30+log [ HCO3− ] −log [ CO2]

pH=10.09+log [ CO3 2- ] −log [ HCO3-]

***************

### Re: How to make %CO2 solution with Na2CO3 based on its stoichiometric relation & solubility?

Posted: Tue Dec 06, 2022 2:50 am
I dont know this articles, do you have a link.

### Re: How to make %CO2 solution with Na2CO3 based on its stoichiometric relation & solubility?

Posted: Tue Dec 06, 2022 2:57 am
sir...I could not able attach the link here...shall I mail u the highlighted pdf which I have

### Re: How to make %CO2 solution with Na2CO3 based on its stoichiometric relation & solubility?

Posted: Tue Dec 06, 2022 3:12 am
attaching the links here https://onlinelibrary.wiley.com/doi/ful ... /wej.12646 refer materials and methods part...

https://www.sciencedirect.com/science/a ... 9718304134 here refer 2.3 lethal dose analysis

Thankyou so much for your responses....Kindly help me if you know the solution

### Re: How to make %CO2 solution with Na2CO3 based on its stoichiometric relation & solubility?

Posted: Tue Dec 06, 2022 7:19 am
The link don't go in detail, like make up of solutions etc.
Fact is that the calculation was wrong. The CO2 is developed or use by biology process, so I have no idea

### Re: How to make %CO2 solution with Na2CO3 based on its stoichiometric relation & solubility?

Posted: Wed Dec 07, 2022 10:17 pm
I also calculated it is coming wrong....But it is published in a research article...how it would be...i am having the same doubt...
What should I do now...Should i mail and ask the author... or if u know any person who may know the solution kindly let me know....I am requesting you to help me.