The molecular formula shows the exact number of molecules. Therefor, the empirical formula is the simplest formula of the molecular formula
The answer would be , a Chemical change!
As a base is added to an acidic solution, the H+ ions in solution that make it acidic are slowly neutralized into water (via OH-, the base). As these ions are converted into water the concentration of them decreases, so the pH decreases, as they are directly related.
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