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

(a) Arrange the three A- anions in order of increasing base strength.

Video transcript

Hello. In this problem, we are told that three rubidium salt solutions are shown below. We're told to note that the water molecules and the rubidium mines have been removed from the image for clarity were asked which arrangement has the anons in ascending order of base strength. So recall that assault then is formed from the reaction of an acid and a base. So when we put our video um salt in solution it will disassociate form its ions. The cast iron and assault is always derived from the base in the acid base reaction. So this would have been rubidium hydroxide which is a strong base and the anti and inner salt was always derived from the acid. The acid would have been a che A. So this could be either weak or strong. We'll need to look at the images above to determine whether the acid that was used to derive the salt was strong or weak. We call that the stronger the acid the weaker the conjugate base. So if we have a annan derived from a strong acid then it will not undergo hydro sis. So we would have a weak conjugate base. And if we have a conjugate base from a weak acid, it will undergo hydro sis it will form a. J. And O. H minus. So again this is our base water will function as an acid and donate a proton to our base to form A J. And O. H minus. So this will be a stronger trying to get base. So when we're looking for the strength of the conjugate base then we are looking for the presence of A. J. And O. H minus. More stronger the base. And so if we look up above then our B. X. We see that we have three H. A molecules. We have three ana ines and we have three hydroxy sides. In the case of R. B. Y. We have um two A. J. molecules, we have six of our anons and we have to hydroxide. And in the case of R. B. Z, we just have six of our animals present. So for RbZ we just have the apennines present. And so that means that the conjugate base the minus would have been produced from a strong acid and so it's a weak conjugate base. It actually has very little base strength since it doesn't produce any H. A. Or O. H minus in a quick solution. The other two the X and the y minus an eyes both generated H A and O h minus in a quick solution. So they are stronger bases to look at and compare the base strength of these two. We need to look at the number of h A molecules and hydroxide ions in solution. We see that our B. X. Produces the greatest number of acid molecules and hydroxide ions in aqueous solution. That means then that x minus is a stronger base. So luke testing our bases in order of increasing based strength then the essentially has no base strength Followed by Y&X. 10 has the greatest space strength. This is the ordering then of our annan's in terms of their base strength. If we look at our possible solutions, so we're looking for Z less than why less than X. We see then that the correct answer is. D Thanks for watching. Hope this helps.