 OK, so this one, I think, will answer that question. What is the Ka of the hydrogen sulfate? Well, we know the pKa from the pKa table. We've got to get this from the pKa table. And all you've got to do, so pKa is just like pH, where in pH, the p stands for the negative log of something. So in this case, it's the negative log of the H plus concentration. So pKa is going to be the negative log of the Ka. So you're going to use this formula, pKa equals the negative log. So in order to figure out what the Ka is, we've got to isolate that variable. So we've got to multiply both sides by negative 1 first. So we're going to have pKa equals the log of Ka. And then to get rid of the log, you just do the inverse log, which is 10 to the whatever. So on this side, it would be 10 to the negative pKa. And then when you do 10 to the log of Ka, what happens is that cancels both of those out and brings Ka down to the bottom. So it's going to cancel all that out. So it's going to be equal to this Ka. So in other words, Ka equals 10 to the minus pKa. So now all we've got to do is plug in our pKa value and see what we get.