Question

Can any substance has zero ph?

Answer 1

My word....we can even have negative `pH`....

Explanation:

By definition, `pH=-log_10[H_3O^+]`...

So I gots a strong acid, say `HBr(g)` or `HCl(g)`, room temperature gases, and I prepare a `1*mol*L^-1` solution in water.....and these you could do in an A-level lab.

We gots essentially quantitative reaction....

`HCl(g) + H_2O(l) rarr H_3O^+ + Cl^-`

And so `[H_3O^+]=1*mol*L^-1`...

And `pH=-log_10(1)=0`

Conc. `HCl(aq)` is approx. `10*mol*L^-1` with respect to `H_3O^+`. What is its `pH`?