Calculate the pH of a solution that is: 1.5 × 10−2 M in HCl.

Answer 1

In order to solve a question like this you need to remember a couple of relationships pertaining to pH and concentration:

pH + pOH= 14 pH= - log ([H30+] 1X10^-14 = [H30+][OH-]

For this problem in particular you need to connect the fact that HCl is a strong acid and therefore dissociates completely therefore if you have a [HCl] = 0.0150 M then the [H3O+] = 0.0150.

With this in mind you simply use the equation I outlined above to find the pH:

pH= - log(0.0150) = 1.82

Hope this helps!