Given that a base has a K b value of 8.36×10 −4 , what is the K a of its conjugate acid?

Hello. Everyone in this video we're given the K. Value for C. Five H. 10 N. H. Were being asked was the value for K. Eight. So let's go ahead recall that Kw is equal to K. A. Times R K. B. You can see for the ion that were interested in. So C. Five H. 10 N. H. Two plus. This is the conjugate acid four C. Five H. 10 and H. So because of this we want to know or we can see that we're solving for basically our K. A. Value here. So we go ahead and divide both sides by KB to isolate our K. A. So we do so we can see that K. A. Is equal to K. W. Over K. B. So we know that both of these values here so we can go ahead and just plug in this value as well as r kelly you w that's already known into this equation. So for K. W. That's one times 10 to the negative 14 aqui B. Value that is given to us since 1.33 times 10 to the negative three. So once you put those values into the calculator we see that K. A. Is equal to 7.5188 times 10 to the negative 12. Of course we want to put our final answer in the correct amount of significant figures. So that's of course three. We'll wind it out at this one here which I'll underline. So looking at the next value here we have an eight. So go ahead around this 1 to 2. So my final answer that for my K value is 7.52 times 10 to the negative 12. So this right here is going to be my final answer for this problem.