Does tap water contain dissolved oxygen and nitrogen; does it contain ionic solutes?
I would think so........
Tap water derives from some reservoir, which is (conveniently) located somewhere in the neighbourhood which is at a HIGHER altitude than the destination tap. (If it was not at a higher altitude the water would not flow out of the tap!). Because the reservoir is open to the air, some of the atmospheric gases will DISSOLVE in the water; and this is a function of water temperature.
The tap water contains some ions.....and also some dissolved gases, i.e. oxygen, nitrogen, and carbon dioxide. There are some places in the world (and you find these when you travel), where tap water tastes extremely good; I am thinking maybe the Pacific North-west of the States and Canada, where it even comes from the tap cold. In other places, for instance Engerland, the tap water does not taste so good. Certainly tap water contains oxygen and nitrogen....., and these concentrations may be measured.