Question

A compound has a pKa of 7.4. To 100mL of a 1.0M solution of this compound @ pH 8.0 is added 30mL of 1.0M HCl. What is the resulting pH?

Answer 1

This is supposed to be review material for me, but I barely remember how to go about solving this stuff, lol! Would I need to do an ICE table? I feel like that isn't the case, because I don't know what one compound is...

Answer 2

Then I remembered about the Henderson-Hasselbach equation but that's not really helping, hahaha... Thinking maybe use the pH to kind the concentration and added that to the concentration of the HCl, but the HCl has such a high concentration that it's almost meaningless. If the pH is within 1 unit of the pKa then it's a good buffer, right?

Answer 3

pH = 7.4 simply means your substance is a base.

Write it as \(B\), and write down the equation it undergoes with \(HCl\)
Then use the new amounts in the Henderson equation.

Answer 4

"Write it as B"? What's B?