Using values of Ka in Appendix C, calculate values of Kb for
each of the following ions.
(a) Fluoride ion, F-

Question

Using values of Ka in Appendix C, calculate values of Kb for 
each of the following ions. 
(a) Fluoride ion, F-

Accepted Answer

Well everyone in this video we're given the value for K. For hipaa Cloris acid, which has a formula of H. C. L. O. And this value of K is 2.9 times 10 to the negative eight. And this question we're being asked, what is the value of K. B. For this ion here? Alright, so let's go ahead and recall that K. W is equal to K. A. Times R K B. Since we're solving for K. B. And we know we're solving for K. B. Because this ion here is the conjugate base of hipaa Cloris acid. So this here is basically taking away our hydrogen adam believes this as being a negative one charge. And of course that's an ion. Alright, so we're starting again for KB. So we can isolate KB by dividing both sides of the equation by K. A. This gives us the new equation to be that KB is equal to K. W. Over K. A. All right. So, we know all these values already. So we can go ahead and simply plug in these values. So K W is one times 10 to the negative 14. And my K value is given to spread over here. That's 2.9 times 10 to the negative eight. So once I put those values into my calculator we can see that KB is equal to 3.4483 times 10 to the negative seven power. But of course we want this answer to be in the correct amount of significant figures which is to so to finalize my answer we can round up to right over here. We see the next digit over is four, so the final answer is going to be equal to 3. times 10 to the -7. So this is going to be my final answer for this problem.

Using values of Ka in Appendix C, calculate values of Kb for each of the following ions. (a) Fluoride ion, F-

Verified Solution

Key Concepts

Acid-Base Equilibrium

Conjugate Acid-Base Pairs

Calculating Kb from Ka