00:01
To determine the p of the silver ion concentration, we recognize first what is going to be in excess.
00:09
We have silver thioscyanate, which as a solid, separates into its ions according to ksp, where ksp is equal to the two concentrations multiplied by each other, and that value is 1 .03 times 10 to the negative 12.
00:37
So when we mix a solution of these two with such a small ksp value, the equilibrium lies very far to the left, creating almost exclusively solid.
00:48
So we need to calculate which is in excess, and it turns out that we've got 25 milliliters of 0 .05 molar silver nitrate and 35 milliliters of half that concentration, 0 .025 molar thioscyanate in the form of ammonium thioscyanate.
01:09
So the silver is going to be in excess.
01:11
So we calculate the excess silver concentration by taking the moles of silver we started with, 25 milliliters or 0 .025 liters, at a concentration of 0 .0500 moles per liter.
01:28
We then subtract off the moles that react, which will be equal to the moles of thioscyanate that we mixed with the silver nitrate, the reaction being one to one...