pH - Weak Bases

Whenever these questions are asked, they are worth Excellence. This is because there are six key steps to remember, and they need to be remembered in order!

1. Write out the equation for the base acting as a an alkaline solution.
2. Write a K_b expression.
3. Calculate K_b from K_a
4. Calculate [OH^-] from the K_b expression (assuming [HB⁺] = [OH^-]
5. Calculate [H₃O⁺] from [OH^-], using K_W
6. Calculate pH

This video is very long, so use it to work through an example, rather than trying to learn it all in one go: