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This is an addition to the Making the Bestest Sugared Drink.
Here, we will be introducing another flavor in form of citric acid,
C6H8O7 or H3C6H5O7
(called triprotic acid since 3 of H are used as H+ and the other 5 do not). What the chemical actually looks like, go to [Structural and Molecular View of Citric acid]. You can see from this link that 3 of the H's are bonded to O-C=O which pulls the electrons away from H and let "it fall off" as H+, called an "acidic hydrogen". The other 5 do not and are not used in producing hydronium ions).
So for a first try, you will not be making your "Bestest Sugared Drink" recipe but instead will be using straight water. Again, the teacher will tell you the maximum amount of citric acid you can do on the first try.
Of course, you will mass that amount out and add it to the water to form the citric acid solution. The difference here is that you will put "a little of the solution in a small cup and you will check
a) the pH with the pH paper
b)the pH with pH probe, if available).
Of course, you have to drink the rest of the solution before making another try.
When you get the correct "sourness", then add that "recipe" to the your "Bestest Sugared Drink" recipe to come up with the new recipe. At this point, if you want to try to improve your taste, you will keep making the combined drink.
For each citric acid drink, in addition to the Molarity calculation to the determine the citric acid molarity, you will calculate the pH of the solution. You will make two assumptions to complete the pH calculations, 1) that citric acid is a strong acid which it is not, it is a weak acid and 2) that one molecule of citric acid produces 3 hydronium ions (actually it is not an assumption it is correct).