00:01
Solubility of the salt can be reduced from its solubility product constant where pbf2 which is a sparingly soluble salt dissolving into pb2 ion and fluoride ion, the ksv at a certain temperature is given to be equal to 2 .69 times 10 to the negative 8.
00:29
Now if this salt is dissolved in a solution containing naf that is a concentration of 0 .7 molar and volume of 750 so we note that we will be able to find a fluoride ion concentration from that solution.
00:45
So first let us establish the ksv expression.
00:49
Ksv is the product of the concentrations with equilibrium of the ions raised to the respective coefficients in the bias equation so we have here ksv equals pb2 plus times f minus squared.
01:03
Here we have the concentration of f minus to be equal to the concentration of naf that's 0 .7t.
01:10
So we'll be solving for the pb2 plus here.
01:15
Ksv is 2 .69 times 10 to the negative 8 equals pb2 plus times 0 .7t squared.
01:24
We solve for pb2 plus then and we get 2 .69 times 10 to the negative 8 divided by 0 .7t squared.
01:37
We solve for this and we get 5 .49 times 10 to the negative 8 molar...