Trader Joe's Alkaline Water

So, Trader Joe's is selling alkaline water.

You know, just in case you need that stuff.

I happened to be over at the TJ's recently and took a photo of the back of the bottle to see what ingredients were that made it alkaline.

Potassium carbonate, potassium bicarbonate, and magnesium sulfate...simple enough then.

In AP chemistry we discuss the pH of salt solutions, and the first two of those salts are pretty straight forward.

K⁺¹ + H₂O --> KOH + OH^-1

Not gonna happen because that would involve the creation of a strong base solution (KOH) something that isn't feasible.

The anions, however, do react with the water to form alkaline (basic) solutions.

CO₃^-2 + H₂O <--> HCO₃^-1 + OH^-1

HCO₃^-1 + H₂O <--> H₂CO₃ + OH^-1

They would, indeed, make alkaline solutions because they're remaking weak acids.

The third salt, magnesium sulfate, is a little more complicated as both ions form weak acid/base solutions. There the K_a and K_b values have to be considered.

Mg⁺² + 2 H₂O <--> Mg(OH)₂ + 2 H⁺¹

SO₄^-2 + H₂O <--> HSO₄^-1 + OH^-1

The water, then, is definitely alkaline/basic. Is there, however, any advantage to drinking alkaline water? That's a different question entirely.

At this point, I'm certainly skeptical on the values of drinking alkaline water based on my brief bit of research. The folks who promote alkaline water seem to fit a lot of characteristics of snake oil salesmen.

I will be using the alkaline water in AP chemistry next year, however, and asking the students to explain the pH effects of the dissolved salts.