Eli5: why is ph scale 7 considered the neutral point?

Question

So why is 7 the neutral value on this scale?

Wouldn’t it been easier to have it as 0 so every negative number was considered acid and so on?

In: Chemistry

Answer 1

pH is literally the negative log of the concentration of hydrogen (H+) in water at that condition. The thing is, even in basic conditions, you have a lot of it. 7 is only neutural because at that value (in water) it’s equally balanced by the amount of (OH-).

There’s a lesser used scale of pOH which uses an “inverted” value. And, pH can go outside of 0 and 14, since it’s a logarithmic expression of concentration, not an arbitrary scale.