I have this long online lab that I am working on and I am stuck onconverting Mol
ID: 75161 • Letter: I
Question
I have this long online lab that I am working on and I am stuck onconverting Molarity then ultimately finding the % of phosphoricacid in the cola? There is all of different steps I went throughwith information but I am going to try to give only the info neededto help me out. (hopefully I do not miss any)Coca-cola contains acids including carbonic acid which is formedfrom the dissolution of the carbon dioxide in the water, andphosphoric acid, which is used to give it a little“kick” when you are drinking it.
The chemical reactions for the titrations of the acids are givenbelow.
H2CO3(aq) + 2NaOH(aq) Na2CO3(aq) + 2H2O(l)
H3PO4(aq) + 3NaOH(aq) Na3PO4(aq) + 3H2O(l)
My unanswered questions:
Give the molarity of phosphoric acid in the original cola?
What is the density of the cola?
What is the % phosphoric acid in the cola?
Some helpful data:
Pipet 2.0mLs of the decarbonated cola into a 100mL volumetricflask. Add 10mLs of the ammonium molybdate/vandate solutionand fill to the mark with distilled water. This will be yourunknown.
Using McVc=MdVc, calculate the molarity of phosphate in theoriginal cola. The answer was .0063 using
Mc=?
Vc=2.0mLs
Md=.00126
Vd=100
If this is not enough info can you please let me know what I ammissing and I will re post with more info.
Thank you
Explanation / Answer
The molarity of phosphoric acid in the cola = 0.00126 M * 100 mL /2 mL = 0.063 M . So check your values for the one missing decimal place. . If the answer is 0.0063 M, it means there are 0.0063 moles ofphosphoric acid in 1 Liter of cola. Mass of phosphoric acid = moles * molar mass = 0.0063 * 97.99 g/mol = 0.617 g . So percent phosphoric acid in the cola will be 0.617 g in 1 Literor 0.0617 g in 100 mL. i.e. 0.0617 % (this is mass / volume percent). . Density = mass/ volume To calculate density,we require the masses of all the substancesdissolved in the cola. Dividing them by the volume of cola they arepresent in will give the density. Hope this helps.