What we want to find is that equilibrium concentration of this guy, this guy and this guy. Then we plug that in into our equilibrium expression and find our Ka. And then we find the PKA by using logs. So we know that we begin. Our initial condition is 0.3 molar of Betonic acid. So our initial condition is we have 0.3 of this guy, we don't care about this guy, we have none of this guy.