We've talked about titrations as well as titration curves in the past. Now we're dealing with redox titration curves. We're going to say here a redox titration curve follows the change in either the analyte, which is coined your titrant, or the titrant itself's concentration as a function of the titrant's volume. So as we're adding our titrant volume by volume, we're going to see a change in the concentration of either species. Now with all titrations, whether they be acid-based titrations or redox titrations, we should always first determine what our equivalents volume of our titrant will be.

So here we have the titration of 50 ml of 0.100 molar sodium chloride with 0.100 molar silver nitrate. Here would produce our precipitation reaction. What happens here is that Na^{+} would combine with the NO_{3}^{-} here. But based on solubility rules, that would give us an aqueous compound. Here, we're concerned with the silver ion combining with the chloride ion to give us silver chloride. Remember, when dealing with a precipitation reaction, we're really talking about K_{sp} of the ionic compound. So remember, K_{sp} deals with the solid ionic compound breaking up into its ions.

Here in this equation, what I've done is we've reversed the reaction. So now, my products are reactants and my reactant here is now a product to show the formation of the solid. Here, this K represents our formation constant. It is actually the inverse of my K_{sp}. So K here is actually 1 over K_{sp}. Remember here, when we reverse the reaction, we get the inverse of our original equilibrium constant. So for this original breakdown of my ionic solid, we had K_{sp}. Because I reversed the reaction, it now becomes 1 over K_{sp}, which is represented by this formation constant here.

The fact that it is a number much greater than 1 tells me that the formation of this solid is highly favorable, which makes sense because based on solubility rules, silver when it combines with the chloride ion definitely forms a solid precipitate. Remember, in terms of calculating the equivalence volume, here we'd say the molarity of my analyte, which we'll say is a times volume of my analyte equals the molarity of my titrant times equivalence volume of my titrant. And when we're calculating the equivalence volume, we're looking for the volume of the titrant. So you'd plug in 0.100 molar of my analyte times its volume equals We know that the first compound is the analyte because we're seeing the titration of this with this. So we're adding this to it. We have 0.100 molar times the equivalence volume of my titrant. Divide both sides by 0.100 molar. So my equivalence volume of my titrant equals 50 ml. So that's the first step in terms of our redox titration. Gathering all this information, overall, will help us determine what our titration curve would look like once we've calculated all different points in terms of the titration.

Now that we've covered equivalence volume, move over to the next video where we take a look at calculations before we reach the equivalence point.