Use the values of Ksp in Appendix C to calculate the molar solubility of the following compounds: (b) Mg(OH)2

Video transcript

hi everyone for this problem. It reads if the value of the solid ability product constant for lead to iodide is 9.8 times 10 to the negative nine what is its moller solly ability. So we want to calculate moller solly ability and the way that we're going to do this is we're going to solve for X. Or calculate for X. Which is going to give us the value for Moeller solly ability. And by calculate for X, we're going to create an ice table. Okay, so let's start off by writing out a balanced reaction. So our reaction balanced is going to be the following. And with this we can create an ice table. Remember that solids are ignored in the ice table. So we're just going to go ahead and ignore this. We have zero product. Okay, so that means our reaction is going to move in the forward direction and we're going to create product. So for our change, our initial is zero moller. For a change because we're creating product we're going to have a positive and we only have one mole. So this is going to be plus X. And this for the second product, our change is plus two X. So then we have X and two X. Now let's go ahead and write R K S. P expression, which is our solid ability product expression and this is going to equal and note that solids are ignored and concentrations is raised by the stoke E O metric coefficient. So are solid ability. Product constant is going to equal the concentration of products over the concentration of reactant. And when we do this, what this equates to is it's going to equal the concentration of products which we have our ions here raised to their coefficients. And because we don't include solids and the expression this is going to be all over one. So let's go ahead and write out. We know what the K. S. P. Expression or value is is 9.8 times 10 to the negative nine. So we have 9.8 times 10 to the negative nine, which is our key sp expression. This is this right here is going to equal now we're gonna plug in what's in the equilibrium row of our ice table for these two values here. Okay, so for the equilibrium row of our ice table, we have X times two X squared. Okay, so now what we're going to do is we're going to solve for X because when we solve for X, that's going to give us the solar cell ability. Okay, so let's go ahead and simplify this so that we can calculate for X. So when we simplify this, what we get is 9.8 times 10 to the negative nine is equal to. So this essentially is X times four X squared because we're foiling this out. Okay, so we have X times four X squared. So now the right side becomes four X cubed is equal to 9.8 times 10 to the negative nine. Okay, so let's divide both sides by four. And we're going to raise Yes. So we're going to divide both sides by four. And what we're going to get is X. is equal to 9.8 times 10 to the -9, divided by four, raise to one third so that we can get rid of the cube. Okay? So this is gonna all be raised to one third. So then what we get is X is equal to 1.3481 times 10 to the negative three. And so our final answer is 1. times 10 to the negative three molar. This is going to be the molar soluble itty. That is it for this problem. I hope this was helpful.