The main concept in this problem is soluble ity of calcium fluoride and the common ion effect. Um, that's what we're going to discuss in this video. Um, the Celje bility reaction of calcium fluoride is shown here a top, Um and so we'll take a look. What we know is that this the fluoride ion is a weak base. Okay, so we'll just take a look at, um, the different solutions, and I will find which one is the would dissolve the most and which one would dissolve the least. So this 1st 1 we have florid as a common I on. And so since it's a common eye on it, uh um, it will only slightly dissolve. Get okay. Now for this one, the sodium hydroxide, the psyllium is just a spectator ion, so we don't really care about it, But the hydroxide is a base. It's ah, strong base, in fact, And so the floor rides, actually, um, this will actually push the equilibrium backwards, and so we will produce more. Um Ah. Sorry. We will produce more florid ions. Okay, Now for the 0.1 Mueller hcl This one, Um when you add an acidic solution. The H plus the hydrogen ions removed the hydroxide ions from the solution. So the base equilibrium reaction moves toward the right side and by consuming fluoride ions and on this indicates that more will dissolve. And so the answer for which one dissolves the most is the HCL right here. It's this one, um, and this one right here as a common ion of calcium, and it has a hydroxide. And so this one actually dissolves the least the I'll just right up here most and least, okay?