PH is a measure of how acidic/basic water is. The range goes from 0 to 14, with 7 being neutral. pHs of less than 7 indicate acidity, whereas a pH of greater than 7 indicates a base. The pH of water is a very important measurement concerning water quality.
Well. Yeah. Basically.
1 mole of any gas is 22.4 L.
Not really sure if that answers your question but that's what i know.
Anyway if we are talking about the size then usually gases are filled with empty space.
Because im pretty sure the molecules would just fall apart like salt which is ionic