 sure yeah okay so this next problem on the worksheet says it is found that 1.1 times 10 to the negative 2 grams of strontium fluoride dissolves per 100 mils of a quiss solution at 25 degrees Celsius. Calculate the solubility product for strontium fluoride. So solubility product do you remember what that is? KSP. KSP right so how do we calculate KSP what do we need to calculate KSP? The concentrations. Yeah so we're going to have to take this and get the chemical equation right so in order to figure out all of that right so okay so like you said the concentrations over here but we've got to know what they are right so what would be one of them here? Um strontium 2 plus. Very good yeah strontium 2 plus on the island. And can you do the other one or should I help you? Uh 2 F. Yeah so the 2 fluoride on the island. So what are we saying here for every 2 fluorides that come into contact with one strontium 2 plus right we get one strontium fluoride okay so from that we should be able to figure out well what's the KSP right so I'll just write it down if you have any questions about why it is just let me know right so this 2 there comes from the coefficient and in fact since there's no superscript here we know that the coefficient there is one okay so we're going to have to figure out the concentrations of these things okay but we have grams and milliliters so from that that's grams and milliliters of the solution of strontium fluoride not of strontium 2 plus and fluoride ions okay so we're going to have to convert all of this information to useful information to plug into this okay so let's do that so I took the liberty of calculating the molar mass of strontium fluoride earlier let's write that down so we have this many grams okay I get 8.8 times 10 to the negative bit moles of strontium fluoride okay but that's not the molarity okay or the molar solubility whatever you prefer so how do we do that well we're going to have to take the moles and divide it by the volume right but we're going to have to convert that volume to liters so if you want to think about it we can do that now so for every thousand mills we have one liter so we're going to take that the moles so we'll just say moles per liter for molar solubility okay it's going to be 8.8 times 10 to the negative moles put it at the moles of strontium fluoride and then divide that by 0.1 zero zero liters of solution so when we do that that should give us 8.8 times 10 to the negative 4 moles per liter strontium fluoride so that's going to be the molar solubility okay so that makes sense so if you want to calculate that okay if you can't do that in your head okay so that that is effectively if you want to think of it like the concentration of strontium fluoride in this equation here so we're going to have to figure out well well we know this concentration of strontium fluoride but we're going to have to figure out now the concentration strontium 2 plus and the concentration of fluoride ions right so let's just kind of say maybe that will help us out in thinking about it okay so we want to know well if we know the concentration of strontium fluoride what's that concentration of strontium 2 plus ions well it's a one to one ratio here in the chemical equation so we're going to have a one to one ratio of these things okay so it's going to be 8.8 times 10 to the negative 4 molar str 2 plus okay and remember in brackets is molarity okay so how do we figure out fluoride though okay so it's not squared right we're going to use the coefficient here and multiply it by okay so we know this multiply it by that coefficient if you want to think about it formally it would be something like this here let's just say molarity so for every one molar and two molar half molar okay does that help you out thinking about it or you probably could have done that on just to put a 2 in front of it on a test it makes it makes it a lot faster right but it's good to think about it so it would be our concentration of f minus it would be two times that so two times 1.8 times 10 to the negative 4 molar okay so now we have this and we have this and we want that so let's just pull each up okay so ksp is going to be jontan 8.8 times 10 to the negative 4 and remember ksp doesn't have units so let's not stick them in there as to confuse ourselves 1.8 10 to the negative 4 we got to square that one so I'm just going to go ahead and square that multiply by and the ksp again you should expect it to be a very small number so if you get a large number then you know you've probably done something incorrect um and in this one it's going to be 2.7 times 10 to the negative 11 so that's the ksp of strontium fluoride at 25 degrees Celsius okay are there any questions on that one or okay none whatsoever you guys would go with that you guys want to get out of here okay kill it thank you