I think it was Angela Collier that did a pretty basic test with a common store bought alkaline water, a lemon and some test strips. The water doesn’t start very alkaline at all.
She did the math (with some assumptions), but basically 0.25 mL of lemon juice will turn 500 mL of alkaline water into neutral water:
This is in the video at 13:16.
The reason is that pH is a logarithmic scale. Alkaline water has a pH of about 8, which means it has a tenth of the hydrogen ions compared to neutral water at pH 7.
Lemon juice has a pH value of 2, which is 1,000,000 times more hydrogen ions than there are in pH 8. So, you just need a little bit of lemon juice to increase the hydrogen ions in alkaline water tenfold, which makes it neutral.
0.25 mL of lemon juice is probably too much already.
She’s doing the maths for the concentration of citric acid in lemon juice through the formula C(acid) = 10^(-pH). That works fine for a strong acid, because you can be pretty sure all that acid in the solution is dissociated, and thus lowering its pH… but citric acid is weak - and weak acids don’t dissociate properly in already acidic conditions.
This means there’s probably way more acid in that solution than the pH makes you believe, but that acid will react once you raise the pH, by mixing the lemon juice into the water.
(I don’t blame her for using the strong acid maths. It’s already enough to convey her point, plus the maths for weak acids is a bloody pain.)
Even regular neutral water shift to slightly acidic (5.6) as long as it have contact to air (CO2 dissolving). Would be interesting to know how long those store bought alkaline water becomes base or acidic.
I think it was Angela Collier that did a pretty basic test with a common store bought alkaline water, a lemon and some test strips. The water doesn’t start very alkaline at all.
edit: Yep, here we go. https://youtu.be/rBQhdO2UxaQ
It’s an amusing video.
She did the math (with some assumptions), but basically 0.25 mL of lemon juice will turn 500 mL of alkaline water into neutral water:
The reason is that pH is a logarithmic scale. Alkaline water has a pH of about 8, which means it has a tenth of the hydrogen ions compared to neutral water at pH 7.
Lemon juice has a pH value of 2, which is 1,000,000 times more hydrogen ions than there are in pH 8. So, you just need a little bit of lemon juice to increase the hydrogen ions in alkaline water tenfold, which makes it neutral.
0.25 mL of lemon juice is probably too much already.
She’s doing the maths for the concentration of citric acid in lemon juice through the formula C(acid) = 10^(-pH). That works fine for a strong acid, because you can be pretty sure all that acid in the solution is dissociated, and thus lowering its pH… but citric acid is weak - and weak acids don’t dissociate properly in already acidic conditions.
This means there’s probably way more acid in that solution than the pH makes you believe, but that acid will react once you raise the pH, by mixing the lemon juice into the water.
(I don’t blame her for using the strong acid maths. It’s already enough to convey her point, plus the maths for weak acids is a bloody pain.)
Facts baby :)
That girl can rant. Love her work, but always watch it at 2x to maximize the frustrated-teacher vibe.
Even regular neutral water shift to slightly acidic (5.6) as long as it have contact to air (CO2 dissolving). Would be interesting to know how long those store bought alkaline water becomes base or acidic.