The following pictures represent solutions of three salts NaA (A- = X-, Y-, or Z-); water molecules and Na+ ions have been omitted for clarity.

(c) Which A- anion has the smallest value of pKb?

Video transcript

Hello everyone today. We are being given the falling problem shown below our solutions of three salts. So you have K. You have that a minus is equal to the c minus D minus and the minus. For simplicity the water molecules and the K plus ions are potassium ions were removed from the representations determine which acids or a minus has the lowest PKB. So how do you want to set this up? Essentially we're going to have our acid react with our water and this is going to form our conjugate base or our asset and our conjugate base here. So a strong conjugate base yields as many conjugate acid molecules and hydroxide ions as is permissible. And so essentially the one with the greatest number. So we can say that the higher or the greater number of conjugated acid molecules contributed asset of molecules and hydroxide ions you will have the strongest conjugate base or C. B. So the stronger the conjugate base, the larger the K. B. Value and the smaller the PKB value is because P K. Has an inverse relationship with our KB. So if we look at these diagrams separately, we look at our K. C. Diagram. 1st we note that we have six of these yellow circles and yellow circles represent our a minus, we see that we have to h A molecules or our white and yellow circles and then we have two hydroxide ions or are two red and yellow red and white molecules. If we look at K. D. And K. E. First looking at K. D. We have four over her acid or a minus, we have three H. A. And then we have three hydroxide. And then lastly for our K. E. We have eight of these acids, One conjugate acid or H. A. and then one hydroxide ion. And so which out of these, which one represents the greatest number of conjugate acids and hydroxide. So that's actually going to be K. D in K D. We have three of these conjugate acid molecules and we have three of these conjugate three of these hydroxide ions. Thus we can say that D minus or the answer VB but D minus is the strongest conjugate base that has the largest KB and subsequently the lowest PKB. And so D. Is going to be our answer. Overall, I hope this helped and until next time.