Determining CO2 in soft drinks by titration (1 Viewer)

[hgill98]

Hey I just needed help with my prac as I don't know what to hypothesise. In my prac I firstly attach a balloon filled with 40mL of NaOH to a flask with 100mL of softdrink and then titrate the contents in the balloon the next day with HCl. I titrate twice, the first time with phenophtalein (for NaOH) and the second with methyl orange (for NaHCO3).Then calculate for the amount of co2 in the sample. Originally I had hypothesised that the higher the sugar content levels in the softdrink the more carbon dioxide as the high levels of co2 might be added to mask the sugary flavour. But apparently after some research coca cola has the most carbon dioxide in it and from the four softdrinks I'm testing it does not have the highest sugar level.
Fanta: 11.2g / 100mL As can be seen Fanta has the most sugar -
Pepsi: 11g / 100mL
Coca Cola: 10.6g / 100mL
Creaming Soda: 10.2g / 100mL
So what do you think would be a suitable hypothesis or if not how could I possibly justify the fact that coca cola has less sugar but a higher carbon dioxide level. - I am yet to do the experiment but would love some advice.

 

[Librah]

What's the aim of your experiment?

 

[hgill98]

The purpose of the experiment is to measure the quantity of carbon dioxide in carbonated beverages, by conducting acid-base titrations. Hence, stoichiometric calculations from the reactions enable comparison of the carbon dioxide levels in carbonated drinks of varying sugar content levels.

 

[Librah]

I don't see why you'd need titrations to do this, can't you just allow the co2 to escape then measure the mass of the flask before and after, then calculate concentration from that?

 

[someth1ng]

I don't see why you'd need titrations to do this, can't you just allow the co2 to escape then measure the mass of the flask before and after, then calculate concentration from that?

This, you could add a small amount of acid to speed it up (obviously, measure the mass of acid).