Would water ph change depending on the freshness of it?

Question

would water ph change depending on the freshness of it?

freshy distilled water is 7ph if i kept that water in a bottle for a few weeks or so would ph change? and if it would, it would become more alkaline or acid?

Answer 1

referring only to rainwater;this ordinarily contains carbon dioxide captured from the atmosphere at low temperatures:carbon dioxide makes the rain slightly acid;so that it can,for example dissolve limestone rock.As the temperature rises the carbon dioxide is less able to dissolve and leaves the water and as a result any dissolved limestone is released from the water to form scalein kettles or stalactites in caves.other gasses also dissolve in rain,the most important being NOX(nitrogen oxides)from motor exhausts; and sulphur dioxide from the burning of oil, coalpeat etc.These last are products of our lifestyle and damage health,trees and buildings.To finish all these gasses make water acid,carbon dioxide leaves te water so that the long term PH should return to near 7;the sulphur dioxide however which has dissolved to form slphurous acid may oxidise in the water to sulphuric acid and the PH will be lower and remain lower;similarly with NOX.

Answer 2

I suppose it could if the bottle was made of a fairly reactive material but it is unlikely it would change any noticeable amount. Whether it was more alkaline or acid would depend on te bottle material. If it is a glass bottle it os not likely any reaction would occur. A plastic bottle may release phenols which would probably lead to a slightly acidic mixture

Answer 3

Depends on if the water is kept tightly sealed under nitrogen or some other inert gas, or is exposed to the atmosphere.

Over time, freshly distilled water exposed to the atmosphere will dissolve small quantities of carbon dioxide gas, generating carbonic acid (H2CO3), and slightly reducing the pH, as well as nitrogen oxides, sulfur oxides, and other gases that could form acids in solution.