Quote Originally Posted by georg16nik View Post
Quote Originally Posted by Katie View Post
Also - how does air have ph value? I know soil and water does, but that's where it ends for me.
The same way as human breath have pH.
Check Your saliva pH with a litmus and You will get the idea.
Katies question is very valid, just take a look how pH is defined. Based on that definition people started calling anything which might behave like an acid when dissolved in water as "low pH" and anything which could possibly behave caustic as "high pH".

In other words, "low pH breath" and "high pH solids" are nothing but careless use of chemical terminology.