number 12 use solubility products and predict which of the following salts is the most soluble in terms of moles per liter in pure water and then they give us these four ionic compounds so we're dealing with caf2 hg2 cl2 pbi2 and snoh2 okay so we have to use the solubility products which i pulled up for you guys solubility product sp solubility product is just the ksp values so i wrote down all the ksp values for the four individual ionic compounds now we just have to figure out which one out of these four is the most soluble and when they say most soluble they're basically just saying which one out of these four dissociates into its ions the most or basically will form the most you know the most ions in equilibrium so it will dissociate or dissolve the most well we have to first figure out whether we're dealing with an even playing field here fingers crossed because then this this uh question gets a little bit chat more challenging and i just noticed that this is hg2cl2 there should be a two here so i'm just going to add that okay beautiful okay so in order to do this we first have to find out how many ions of each these compounds will break down into so let's just start with caf2 right caf2 the break would be between the calcium and the fluorine right and this will break down into calcium and the fluorine right ca in group two so that's a two plus fluorine is in the halogen group that's always a negative one charge you could also find these charges by you know doing the crisscross rule one goes up to the flooring two goes up to the calcium but now the most important part is just saying how many you have of each now here i have two fluorines so i know that i have to put a two in front of the f there was only one calcium so one calcium so the total amount of ions is one of these and two of these one plus two is a total of three ions so we have to do the same thing for the other three of these now hg2 cl2 is a tricky one because hg2 is its own polyatomic so this too won't crisscross up to the the chlorine there was one hg2 so if i just say okay what's going to be the ions that this breaks up into well we have the hg2 and it just started downpouring here so sorry if you hear that in the background but i i actually like the sound of you know water on the the windowsill i like the sound of rain anyway hg2 cl right cl is a minus one charge and the two crisscrosses up telling me that the hd was a plus two charge we have to find out how many we have of each there was two chlorines so i put a two in front of here there was only one hd2 so one of these so one plus two again is three ions okay so far so good let's just do the other ones right we have lead and iodine if i crisscross these up or not crisscross them but we have lead and we have iodine iodine just like all the other halogens for ionic compounds would be the negative one charge and then the two crisscrosses up telling me that the um the lead was a plus two there was two iodines so i have two of these one plus two is a total of three ions okay let's see hopefully fingers crossed when we crisscross up tin two hydroxide snoh2 we get sn and oh there was one sn and two ohs so the oh gets a negative one charge the tin gets a plus two and because there was two ohs i know that i have two of these and one plus two is a total of three ions thank goodness these are all the same because if your compounds that you have dissociate into the same amount of ions all you have to do is just look at the ksp values but we have to do this work just to make sure now in the rule that states that you know all the ions are exactly the same the most soluble is always the one in which you have the highest ksp values so that kind of makes sense remember high k values means at equilibrium you favor the products and that's what you'll dissociate the most you'll have the most products so in this case you just have to look at those exponents that's what's different so i have a negative 11 negative 18 negative 8 and negative 27. the most soluble is the highest ksp so just pick the highest number out of the exponents in this case negative 8 is the highest out of negative 11 negative 18 and negative 27. so the most soluble would be pb i 2 and that is it okay no more for this one what do you guys think let me know in the comments subscribe to the channel if you want to help us out and i hope you all have a great day i will talk to you soon okay bye