Question

Where do strong acids and bases fall on the pH scale?

Answer 1

Acids are lower, bases are higher on the pH scale.

Explanation:

When determining the pH of a strong acid or base you should be given a concentration in molarity (moles/liter).

Since strong acids and bases completely disassociate in water you can take the `-log` of the molarity. For example, if you were asked to find the pH of a .058 M solution of `HCl` you would enter `-log(.058)`

You can see that it would have a pH of 1.23

You do the same thing for strong bases, but you have to remember that the answer that you will get will be `pOH`. To get the pH you simply subtract the `pOH` from 14.

For example, if you have a `NaOH` solution that has a molarity of .063 you take the `-log(.063)` and get a `pOH` of 1.20.

`14-1.20=12.79`

From that information you can see that acidic solutions have a lower pH and basic solutions have a higher pH.