well he is right about soda (usually) meaning sodium, and phosphates being different and tasting different... but boy oh boy, that is old time..

i remember having a phosphate once, as a child on some grand trip my parents went on. maybe in some small town on the way to Niagara falls...
phosphates are used in cola, (real Coke that is) at least in diet cola, less than 1% sodium and phosphoric acid is the 4th ingredient, according to the label.

phosphates are sourer than sodium based carbonation.

(lately between reading about corn (and many of the sodium based products that came from corn production, like baking soda) and Uncle Tungsten, my mind is swimming with chemistry!)